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Windows NT Workstation /
John D. Ruley
John Ruley

Catch-22 for NT
You need a DOS boot to load Win95 on NT.

In Joseph Heller's novel Catch-22, an Air Force doctor tells the hero, Yossarian, that he can't get out on a psychological discharge because his asking for one proves he's not insane.

After trying to make an NT 4.0 system dual boot Windows 95, I can identify with Yossarian. I felt boxed in by a bunch of reasonable-sounding but fundamentally crazy requirements. The good news, though, is that you don't have to feel the same way. Like Yossarian, I've found a way around catch-22, and I'll share it with you.

Each of these columns ends by inviting reader feedback. Over the years I've found that reading-and trying to answer-all of my mail is by far the best way for me to keep my finger on the pulse of NT users.

If there's a problem, I can count on readers to find it. And so you have!

Since late last year, I've noticed an increasing number of letters from readers wanting to know how they can install Windows 95 onto an NT system. That's interesting in itself; Microsoft justifies the limited support for dual booting between Windows 95 and NT (and the complete lack of support for upgrading from Windows 95 to 4.0) partly by saying that it's not necessary-aside from programmers, nobody needs both. But let's look at the facts: NT still won't run as many applications as Windows 95, which, in turn, isn't as stable as NT. That's our first catch-22. If you pick either of these operating systems alone, you'll have to give something up.

Until two years ago, practically every new PC came with DOS and Windows 3.x preinstalled. Now Windows 95 is the de facto standard system for new PCs. You can add NT to any of those systems, and setting up a dual boot is simple. Install NT as usual and decline to upgrade any Windows directory you already have. When the NT setup is finished, you'll have a multiboot menu with options for both NT and your previous OS. This is by no means a perfect solution. For one thing, you'll have to install all your applications twice (see my NT Q&A at www.winmag.com/ew/ntqa04.htm, for the gory details). But it does work.

Today, however, some systems ship with only NT preloaded. This reverses the situation. Instead of adding NT to a Win95 system, you'll want to add Windows 95 to an NT system. That turns out to be a tough problem, and the solution takes us into unfamiliar territory.

Win95 + NT = frustration

When I started getting letters on this topic, I came up with a stock answer-which I won't bore you with, because it was wrong. Specifically, it was wrong in step 4, which went like this:

Use a Win95 boot floppy disk and start Win95 setup ....

If you've tried this yourself, you already know where I went wrong. It won't work unless you have an OEM version of Windows 95 that came with a setup disk. The Windows 95 upgrade that's sold in stores has no such disk-it's just a CD, and the setup program on the CD absolutely, positively will not run from NT.

The correct step, then, is: Find a DOS boot floppy disk. You can boot from that floppy and then run Win95 setup from the CD, assuming your DOS floppy includes drivers for your CD-ROM drive. If not, you can copy the contents of the Win95 directory from the CD to your hard disk and run setup from there.

Where do you find a DOS floppy? Well, that depends-if you've been working with PCs for a while, you probably have an old copy somewhere. If not, you have other options. If you're already running Windows 95, use it to make a start-up disk. It will create a DOS 7.0 boot floppy. If you have an NT Server available, the Network Client Administrator tool will make a DOS 6.2 boot floppy-with network support!

But let's take the worst case: Your only system came with NT installed, and you've either never had DOS or got rid of it when you bought NT. What then?


It took a while before I figured out just how complete a catch-22 situation this is. Windows 95 setup will not run from NT, period. A DOS boot floppy disk of some sort is definitely required-and if your system came with NT preinstalled, then it has no DOS boot floppy.

I know, because I have an AST Bravo MS-T 6200 that came with NT Workstation preinstalled. After two long days trying to find a DOS boot image somewhere on the Windows 95 CD, I was just about as frustrated as Yossarian. Then, I had a breakthrough. Remember DOS clones? There were several back in the days before Windows 95. The best of them was probably Digital Research's DR DOS.

The part of the company that made DR DOS is now owned by Caldera, the outfit that thinks Linux is the operating system of tomorrow. They're also true believers in the notion of open systems-so much so that what used to be DR DOS is now called OpenDOS, and is free for noncommercial use or evaluation. You can download it from http://www.caldera.com. I recommend the Lite version because it's a smaller download, and all you give up are NetWare Lite drivers.

"Aha," I thought. "We can substitute an OpenDOS boot in step 4, and we're off to the races!"

Catch-22, redux

When you download and unzip OpenDOS, you'll find yourself with three 1.47MB DISKn.IMG files and a DISKCOPY.COM utility that copies the IMG files onto floppy disks. At least that's what DISKCOPY.COM does when run from DOS. When you try to run it from NT, you get a nasty error message informing you that DOS applications are not allowed direct access to the hard disk.

So, making an OpenDOS boot floppy requires DISKCOPY.COM, which only runs from DOS? If you're feeling like Yossarian, you're not alone!

Fortunately, that's not the end of the story. A little time spent with the disk editor from my NT Disk Utilities (available at www.winmag.com/ew/ntfs.htm) convinced me that the format of those 1.47MB image files was a bit-for-bit copy of a 1.45MB floppy disk, plus 20KB of excess data. Armed with that information, I broke out the development tools and built myself yet another utility. WMDISKCOPY.EXE, also available at www.winmag.com/ew/ntfs.htm, is a native NT program. Its sole purpose is to copy IMG files onto floppy disks. And with that tool, it's finally possible to write those step-by-step instructions.

Note: You'll need both the Windows 95 and NT 4.0 distribution CDs, and from 20MB to 50MB of free space on your C: drive-which must use a File Allocation Table (FAT) format.

1. Download WMDISKCOPY from www.winmag.com/ew/ntfs.htm.

2. Download OpenDOS Lite from http://www.caldera.com/dos/download.html (or you can use DOS boot floppies from one of the other sources I mentioned earlier)

3. Use WMDISKCOPY to make OpenDOS setup floppies.

4. Check your system vendor's Web site for information on Windows 95 support. Find out if you need to reset your BIOS to support Plug and Play and determine whether Windows 95 installation requires any BIOS patches or other upgrades.

5. Optional: Check your system vendor's Web site for DOS-based CD-ROM drivers. If you find them, add them to your OpenDOS system floppies per the instructions in the OpenDOS README.TXT file. If you can't find them, don't worry. You can still set up Windows 95, but you'll need about 50MB of extra hard disk space.

6. Make sure you have an up-to-date NT emergency disk. If you don't have one (or haven't updated it since you installed NT), use NT's RDISK.EXE utility.

7. Find the three setup disks that came with NT. If you can't find them, make new ones using the WINNT32.EXE utility on the NT distribution CD.

8. Back up everything that's irreplaceable.

9. Shut down your system. Insert OpenDOS floppy #1 into your A: drive and reboot.

10. Follow the on-screen instructions to install OpenDOS Lite.

11. When OpenDOS setup is complete, insert your NT setup floppy #1 into drive A: and reboot. NT setup will begin.

12. Select the Repair option and follow the on-screen instructions.

13. Reboot when instructed. The NT multiboot menu now lists an "Unrecognized Operating System," which is actually OpenDOS. If you installed CD-ROM drivers in step 5, skip to step 15.

14. Boot Windows NT. You will need approximately 50MB of hard disk space. Copy the entire Win95 directory from the Windows 95 CD to a temporary directory on your hard disk. Shut down Windows NT and reboot the computer.

15. Boot OpenDOS. You will need approximately 20MB of hard disk space. Start Windows 95 setup, either from the CD or the temporary directory on your hard disk where you copied the Win95 directory.

16. Follow the on-screen directions to upgrade from OpenDOS to Windows 95.

17. After completing Windows 95 setup, shut down and reboot your system. The "Unrecognized Operating System" option in the multiboot menu is now actually Windows 95.

18. To rename "Unrecognized Operating System," use ATTRIB.EXE to remove the hidden and read-only settings on the BOOT.INI file in the root of your C: drive and edit it with any text editor. Find "Unrecognized Operating System" and change it to "Windows 95."

19. You may have to take additional steps to make Windows 95 recognize your CD-ROM drive and other peripherals. Consult the Windows 95 upgrade documentation and your vendor Web site for additional information.

If this procedure looks complex, well, it is. That's because Windows 95 and NT are almost completely incompatible as far as setup is concerned. But if you patiently follow the previous steps, you'll survive your catch-22 just as Yossarian did.

John D. Ruley is senior technical editor at WINDOWS Magazine and principal author of Networking Windows NT 4.0, Third Edition (John Wiley & Sons, 1996). You can reach John at www.winmag.com/ew or at the e-mail addresses here.

Windows Magazine, June 1997, page 275.

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