PCs Running DOS: Y2K Readiness Checklist

This page was last updated early during the year 2000 and some or all of its content may thus no longer be current or accurate.

PCs Running DOS: Y2K Readiness Checklist

This checklist discusses Y2K issues affecting industry-standard PCs - typically older models dating from the 1980s or early 1990s - which may still be running the DOS operating system.

For the purposes of this checklist, DOS encompasses any of three commercial operating systems:

MS-DOS (through version 6.22), from Microsoft Corporation.
IBM PC DOS , from International Business Machines Corporation (IBM).
Lineo (formerly Caldera) DR-DOS , from Lineo, Inc. (formerly a division of Caldera, Inc.), and its predecessor products: Novell, Inc.'s Novell DOS, and Digital Research Corporation's DR-DOS.

If you're using Microsoft Windows 95 and 98, see the respective Y2K Readiness Checklists for Windows 95 or Windows 98 for information on Y2K issues relating to the newer versions of MS-DOS (such as 7.10) included with these versions of Windows.

If you're using Microsoft Windows 3.1x, see the Y2K Readiness Checklist for Windows 3.1x for information on Y2K issues relating to its included version(s) of MS-DOS.

Summary

Hardware

Many industry-standard (also known as "Intel-based" or "IBM-compatible") PCs have a minor hardware problem affecting their internal clocks: instead of rolling over normally from 1999 to 2000, these clocks will instead revert to a different year. There are a variety of methods available for finding and resolving this problem.

The Y2K Hardware Problem Affecting Many PCs

Most versions of DOS do not include any features which can correct PC hardware Y2K problems. As a result, you'll need to use some other method to resolve such problems.

There are two exceptions: IBM and Lineo claim that their most-recently-released versions of DOS, IBM PC DOS 2000 and Lineo DR-DOS 7.0x, respectively, incorporate software fixes capable of working around hardware Y2K problems on some PCs.

Very old PC application programs, such as those which run under the DOS and Windows 3.1x operating systems, are substantially more likely than more recent applications to have Y2K problems.

If you are using a critical DOS or Windows 3.1x program which has serious, unresolvable Y2K problems, you might need to upgrade or replace this program. This could in turn require a newer operating system, such as Windows 95, 98, or NT, which could also compel an upgrade to a newer PC.

Operating System

Microsoft's MS-DOS

Microsoft will not be testing MS-DOS versions prior to 5.0 for Y2K compliance.

Microsoft asserts that Versions 5.0 through 6.22 of MS-DOS have three Y2K issues, for which there are no fixes available. These issues are very minor, however, and two of these issues have straightforward workarounds.

MSBACKUP, the DOS-based backup program included with MS-DOS versions 6.xx, has two additional Y2K problems which could cause confusion when performing backups or managing your backed up data. If you happen to have used this program to back up your data, you'll need to look into these problems before the year 2000 arrives.

If you absolutely require a version of DOS which is claimed by its vendor to be 100% Y2K compliant, you may be able to purchase and install either IBM PC DOS 2000 or Lineo DR-DOS.

IBM PC DOS

IBM's latest version of DOS, IBM PC DOS 2000, is claimed by its vendor to be Y2K compliant.

The previous version, IBM PC DOS 7, is claimed to be compliant after applying a Fix Pak. In addition, IBM asserts that all earlier versions of IBM PC DOS, including PC DOS 6.x, are "non-ready." IBM's suggested compliance path for all previous versions is to upgrade to the IBM PC DOS 2000 release, which can be purchased from IBM.

Lineo (formerly Caldera) DR-DOS, Novell DOS, and Digital Research DR-DOS

Lineo (formerly a division of Caldera, Inc.) DR-DOS version 7.03 is claimed by its vendor to be Y2K compliant. (Previously, Caldera had asserted that version 7.02 was also Y2K compliant.)

We were not able to readily locate information on the compliance status of earlier versions of its predecessor products, Novell DOS and DR-DOS. An obvious compliance path for these earlier products would appear to be to upgrade to DR-DOS 7.0x, which can be purchased from Lineo.

Application programs Check for Y2K compliance.

Data files & data sharing methods Check for Y2K compliance.

1. Hardware

1.1. Find and resolve Y2K hardware problems in your PCs running Windows 3.1x.

Many industry-standard (also known as "Intel-based" or "IBM-compatible") PCs have a hardware problem affecting their internal clocks: instead of rolling over normally from 1999 to 2000, these clocks will instead revert to a different year (such as 1980).

While this is generally of minor concern, an invalid date could nonetheless cause problems for certain application programs. A small fraction of these problems could potentially have serious impacts. As a result, it's preferable to find and resolve this problem before the year 2000 arrives. The Y2K Hardware Problem Affecting Many PCs

describes how to do so. Here's a summary:

You can identify which PCs will be subject to this problem by checking with vendors or by using manual or automated software tests.

There are at least ten different methods you can use to prevent the problem from occurring on your non-compliant PCs. Among these:

Running an operating system, such as Linux and recent versions of Windows NT, that incorporates a date correction feature;
Leaving your PCs turned off over the century transition and using a specific procedure to manually set their dates when they are first started up during the year 2000;
Installing small software programs that automatically correct the date;
"Flash" updating the software in the BIOS chips in your recently-manufactured PCs to make these chips Y2K compliant;
Synchronizing your computers' dates over a network;
Upgrading PCs with BIOS add-in cards or other hardware.

Each of these methods has its own particular advantages, limitations, and drawbacks, which are described in the above document.

As a fallback, you can manually reset your problematic PCs to the correct date when the year 2000 arrives. After doing so, all (or nearly all) of your PCs should then continue to maintain the correct date throughout the year 2000 and beyond.

Most DOS versions do not include any date correction capabilities

Most versions of DOS do not include any features which can correct PC hardware Y2K problems. As a result, you'll need to use some other method to resolve such problems.

For example, Microsoft claims in its white paper, Windows Operating System Interactions with BIOS and Real Time Clock , that MS-DOS does not include any features which can correct PC hardware Y2K problems. As a result, you'll need to use some other method, as described above, to resolve such problems. In this white paper, Microsoft suggests that you manually reset your PC's date using the DOS DATE command.

Two recently-released DOS versions do offer some date correction capabilities

IBM and Lineo claim that their most-recently-released versions of DOS, IBM PC DOS 2000 and Lineo DR-DOS 7.0x, respectively, incorporate software fixes capable of working around hardware Y2K problems on some PCs.

IBM notes in PC DOS 2000: Questions and Answers that:

For some machines PC DOS 2000 monitors and corrects the Century Byte that may not be updated when the century rolls over on December 31, 1999. PC DOS 2000 does not attempt to fix any other BIOS-related problem. PC DOS 2000 does not correct the Century Byte for an application that communicates directly with BIOS.

Lineo (when it was formerly Caldera, Inc.) claimed in its statement of Caldera DR-DOS 7.02 Product Information that Caldera DR-DOS 7.0x's "kernel will correct the system date even if your BIOS does not support the Year 2000." The company formerly offered further details in Caldera Year 2000 Solutions :

Year 2000 support in DR-DOS works in the following way:

If the BIOS reports the year in the range 1900 through 1980, DR-DOS sets the century to 20xx. For example, 1900 becomes 2000 and 1917 becomes 2017.

If DR-DOS is running at midnight on 31st December 1999, it still reports the Year 2000, even if the BIOS reports 1900.

There is sufficient ambiguity in the above discussions regarding when, and under what circumstances, the built-in date correction features in these versions of DOS will send a request to your PC's BIOS to update the century counter, that it may still be prudent to use some other method as your primary means of correcting a non-compliant PC's date when the transition to the year 2000 arrives, and to regard the date correction capabilities in these two recent versions of DOS as a backup method.

2. Operating system

2.1 Determine what version of DOS you're running.

When you are at a DOS prompt, which looks something like C:> or C:\>, you can determine which version of DOS you're running by typing VER (short for "VERsion") then pressing the Enter key.

You will then see a message that should look something like the following:

MS-DOS Version 5.00

This message will tell you whether your PC is running MS-DOS, IBM PC DOS, or DR-DOS, as well as the version number for the DOS operating system.

When using DOS under Windows 95 or 98

If you type the VER command at a MS-DOS prompt under Microsoft Windows 95 or 98, you'll instead see a message listing the Windows 95 or 98 version number, which will look something like this:

Windows 95. [Version 4.00.950]

If you see a message similar to the above when you type the VER command, this checklist is not relevant to you. For information on Y2K issues relating to the newer versions of MS-DOS which are included with such Microsoft Windows 95 and 98, see the respective Y2K Readiness Checklists for those operating systems.

2.2 Check your vendor's Web site for the latest updates to its Y2K compliance statement for your version of DOS.

Over time, software vendors have made revisions to the Y2K compliance statements for many of their products. As a result, it's probably a good idea to schedule one or two checks, later in 1999, to see whether your vendor might have once again revised its compliance statement for the version of DOS that you're running. By doing so, you can keep up-to-date regarding any newly-identified problems and fixes.

Y2K compliance statements for DOS products include:

Another way to find Microsoft's Y2K compliance statements for DOS:

If the direct links to Microsoft's Y2K Product Summaries for DOS should later be moved or otherwise don't work, you should be able to navigate to these statements via Microsoft's Year 2000 Product Guide Web page.

On that page, scroll down to the subhead "Search for Microsoft Products." In the list of products below, scroll down to the category "Operating Systems". You may need to scroll down a bit further to see and click "MS-DOS". Then click the "Perform Search" button. This will generate a list of compliance statements for various releases and language versions of MS-DOS.

2.3. Identify and resolve, if possible, the Y2K issues affecting your version of DOS.

Before installing any updates or patches which may alter your computer's operating system software or application programs, and before making any changes to your critical documents (data files), be sure that you have a complete, current backup of your computer's data.

For general backup advice, see the Berkeley Computing and Communications articles
Ask Dr. Micro: How can I back up the files on my computer

If your PC is running Microsoft's MS-DOS

If you're using a version of Microsoft's MS-DOS earlier than 5.0, Microsoft will not be testing your version of this operating system for Y2K compliance. Since the Y2K issues with earlier versions of DOS are unknown, it might be prudent to upgrade to an MS-DOS version 6.x release (which you might able to locate as a used, retail product), or to upgrade to a newly-released DOS product, such as IBM PC DOS 2000 or Lineo DR-DOS.

If you're using MS-DOS versions 5.0 through 6.22, these versions of DOS all have three Y2K issues for which Microsoft will not be providing fixes. However, these issues are very minor, and two of these issues have straightforward workarounds:

The DOS DATE command will not accept two-digit years from 00 through 79, but will accept four-digit years such as 2000 or 2001.
Some 'external' DOS commands that use "switches" (additional information you type as part of these commands) will not accept dates with two-digit years from 00 through 79, but will accept four-digit years such as 2000 or 2001.

(External DOS commands are programs which are not contained within the file COMMAND.COM and thus loaded into memory when DOS starts up, but rather must be individually loaded and run from your PC's disk.)
The DOS DIR command can only display two-digit years when it lists the modification dates for your files.

In addition, if you've used the ancient MSBACKUP program provided with MS-DOS version 6.x (i.e. MS-DOS versions such as 6.0, 6.2, and 6.22) to back up your DOS and Windows files, you should be aware that this program has two additional Y2K-related issues. These do not appear to affect the integrity of backed up data, but do appear to have the potential to cause confusion when performing and managing backups. Microsoft's Y2K Product Summaries for DOS 6.0, 6.2, and 6.22 include a detailed discussion of these two Y2K issues with MSBACKUP.

If you're still using MSBACKUP, we encourage you to switch to another method of backing up your files. For general backup advice, see the Berkeley Computing and Communications article Ask Dr. Micro: How can I back up the files on my computer .

If you absolutely require a version of DOS which is claimed by its vendor to be 100% Y2K compliant, you may be able to purchase and install either IBM PC DOS 2000 or Lineo DR-DOS. (See below for details.)

If your PC is running IBM PC DOS

IBM asserts that all earlier versions of IBM PC DOS, including PC DOS 6.x, are "non-ready," and notes at Steps to Year 2000 readiness of PC DOS that the compliance path for all previous versions is to upgrade to the IBM PC DOS 2000 release, which can be purchased from IBM (below).

The previous version of this product, IBM PC DOS 7, is claimed to be compliant after applying a Fix Pak, available by selecting the "Offering Detail" link from IBM's PC DOS 7 Fix Pak for Year 2000 page. Doing so leads you to a set of FTP (File Transfer Protocol) links for downloading the Fix Pak and associated "readme" file, including:

Year 2000 Fix Pak for IBM PC DOS 7
(for the USA & UK English version of DOS 7, named DOS7USY2.EXE)

Read Me file for this Fix Pak
(for the USA & UK English version of this Fix Pak, named README.US)

The other "migration alternative" offered by IBM for IBM PC DOS 7, other than applying the Fix Pak, is to purchase an upgrade to IBM PC DOS 2000.

IBM asserts that its latest version of DOS, IBM PC DOS 2000, is Y2K compliant. IBM claims that it can be used to upgrade PCs which are currently running DOS 3.3 or later, including MS-DOS. This product can be purchased online via the "Buy other versions" links on IBM's IBM PC DOS: Overview page. When we last visited IBM's Web site on June 9, 1999, this product could be purchased in diskette and CD-ROM packages, as well as additional licenses without media, at prices ranging from $50 to $60 per copy, plus shipping and sales tax.

Another option for users of older versions of IBM PC DOS might be to purchase and install Lineo's DR-DOS (below.)

If your PC is running Lineo or Caldera DR-DOS, Novell DOS, Digital Research's DR-DOS

Lineo asserts that its latest versions of DOS, DR-DOS 7.02 and 7.03, are Y2K compliant. From the descriptions on Lineo's Web site, installation of this product does not appear to require a previous version of DOS.

A 90-day evaluation version is available from Lineo's DR-DOS Free Tryout page. When we last visited Lineo's site on November 17, 1999, this product could be purchased on CD-ROM from the Caldera OpenStore page at a price of $39 per copy, plus shipping and sales tax. (Formerly, Caldera had also offered a diskette-based distribution.)

We were not able to readily locate information on the compliance status of its predecessor products, Novell DOS and DR-DOS. An obvious compliance path for these earlier products would appear to be to upgrade to DR-DOS 7.0x, which can be purchased from Lineo.

3. Application programs

3.1 Check custom-written programs for Y2K compliance.

Custom-written (or "customized") application programs have been written "from scratch" or else extensively modified to perform a customized set of tasks for a specific customer. Some campus departments are running such applications, which typically have been created by departmental programmers or outside consultants. Often, these programs were built using programming or scripting languages, database management systems, or client/server tools.

Custom-written programs are at considerable risk for Y2K problems. Some of these programs may not work properly in the year 2000, or may encounter problems when handling dates from the year 2000 and beyond. If one or more of these programs are of significant importance to your campus department, it is essential that you find and resolve their Y2K problems. It is also imperative that you begin your work as early as possible, as the process of identifying, fixing, and testing fixes to custom applications can often be very time consuming.

Custom Applications: Finding & Resolving Y2K Problems

can direct you to resources to help you find and resolve Y2K problems in custom applications. In particular, you can obtain a great deal of assistance from the Web pages of the UC Berkeley campus's Year 2000 Departmental Customized Applications Subcommittee, which has identified a phase-by-phase process that can guide you in carrying out this work.

3.2. Check off-the-shelf application programs for Y2K compliance.

It appears likely that most commercial off-the-shelf application programs will work fine in the year 2000. However, some application programs are known to have Y2K problems or issues, ranging from minor to severe. If some of these application programs are important to your department or to your own research or instructional work, you'll need to resolve their Y2K problems before the year 2000 arrives. To do this, we suggest that you:

Identify your critical application programs.

Prioritizing: Identifying Your Critical Computers & Software lists representative examples of critical tasks that your computer might be performing, which may help you identify your critical application programs.

To ensure that you're not overlooking any critical programs, Commercial Off-the-Shelf Applications: Finding & Resolving Y2K Problems describes how you can use automated software tools to generate an inventory list of all of the programs installed on your computer.
Determine which of these applications are not Y2K compliant.

You can do this in a variety of ways, including:
- Viewing a list of the Y2K Compliance Status of Selected Off-the-Shelf Applications Used at UC Berkeley .
- Checking vendor Web sites, as well as lists and searchable databases of product Y2K compliance available on the Web.
  
  You can find a summary of these resources in Commercial Off-the-Shelf Applications: Resources for Identifying Y2K Compliance .
- Using automated software tools which report on the Y2K compliance status of your applications.
  
  Software Tools for Finding & Resolving Y2K Problems lists some of the tools you might use for this purpose.
  
  The section on Inventory & compliance status tools in the document Commercial Off-the-Shelf Applications: Finding & Resolving Y2K Problems discusses limitations you might encounter when using such tools.
Resolve problems with non-compliant applications.

Commercial Off-the-Shelf Applications: Finding & Resolving Y2K Problems includes general checklists that can guide you through the process of resolving Y2K problems in non-compliant application programs.

If some of your programs have only minor Y2K issues, you might in some cases be able to continue to use these applications. However, most non-compliant programs will need to be patched, updated, upgraded, replaced, or retired.

4. Data files & data sharing methods

4.1 Check data files for Y2K compliance.

Data files, including spreadsheets and database files, can harbor Y2K problems. If some of these files are important to your department, or your personal research or instructional work, you'll need to resolve their date-related problems before the year 2000 arrives.

The Berkeley Computing and Communications article Checking your data for Y2K problems

provides a overview, and the document Data Files: Finding & Resolving Y2K Problems

describes in somewhat more detail how to check your data files to find and resolve Y2K problems. The following are some key points mentioned in both of these documents:

The primary areas of Y2K-related concern in data files are:

Custom macros, scripts, and user-defined functions.

Some spreadsheet and database files may incorporate custom-written macros, scripts, or user-defined functions which improperly handle dates.
Standard date functions.

Many spreadsheet and database programs provide standard date-related functions which are known to have Y2K-related "usage issues." Examples include Microsoft Excel's =DATE(), Microsoft Access's =DateSerial(), and Lotus 1-2-3's @YEAR().
Dates stored as text or numbers.

Dates stored in spreadsheet cells or database fields as text (e.g., "02/21/15") or integers (e.g., "990405"), may present risks when these values are converted to dates, or when they are compared or sorted.

In addition, we encourage you to take four specific steps to help keep Y2K problems out of your data files

in the future.

4.2. Check data sharing methods for Y2K compliance.

Data shared between application programs could in some cases present Y2K problems. You can find guidance on finding and resolving these problems in Data Sharing Methods: Finding & Resolving Y2K Problems

.

Methods of sharing data which are at risk include documents exchanged via disks, e-mail attachments, and file servers; data copied and pasted via the Clipboard; and programmatic data streams between programs.

To find situations where you'll need to check your data sharing methods for potential Y2K problems, ask yourself three questions:

Do you export data containing century-ambiguous dates, such as "05/13/29", from any of your programs?
Do you import data containing century-ambiguous dates into any of your programs?
Do you share any files (such as spreadsheet or database files) containing dates stored as text or numbers, rather than as dates?

Find something unclear? Missing? Incomplete? Inaccurate? Or even praiseworthy? Send us feedback about this Web site!

This site is provided by the campus Year 2000 Departmental Computers and Administrative Equipment Subcommittee at the University of California, Berkeley.

Copyright 1999 by the Regents of the University of California.
Disclaimer: The University assumes no liability if the information on this page is used for other than University purposes.