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HOME TOPICS ABOUT ME If you install a new program when you're running one version of Windows, the other one won't know anything about that program. The program might run just fine and it might not, depending on a couple of technical factors. |
technofile Al Fasoldt's reviews and commentaries, continuously available online since 1983 Making dual Windows installations, Part 2Aug. 31, 1997 By Al Fasoldt Copyright © 1997, The Syracuse Newspapers Last week I explained the first steps in creating multiple Windows installations. You can use a copy of your entire Windows setup as a safe haven if something goes wrong, or you can create different versions of Windows. Switching from one to the other is easy. Because I'm a nice guy and because I hate to get mail from people who don't follow instructions, I'll make this point even clearer: Read the explanation in the previous article and follow it to the letter. Don't do anything I'm going to tell you this week until you've done what I wrote about last week. Ready? If you've been following things so far, you now have a copy of your Windows folder on your C: drive. I'm assuming that your main Windows folder is named "Windows," but I realize some Windows folders may have different names. If that's the case on your PC, substitute the name of your Windows folder in every example. The copy of your Windows folder should have a short name -- "WINBACK," for example. You should also have a copy of MOVE.EXE in the root (main directory) of your C: drive. And you should have set up Windows 95 to move the swap file out of where it is normally stored. (These steps were explained in the first article.) On to the good stuff. Here's how you switch from one Windows setup to another one. For now, I'll leave out the reasons you might want to switch. (Use your imagination -- or, better yet, think back on how many times you've worked all weekend when you could have done something fun just to get your PC running again after it got messed up.) Click the Start button and choose "Shut Down." Choose "Restart the computer?" from the list. Windows will shut down and the PC will reboot. . As soon as the usual PC messages finish displaying on your screen (and before Windows starts up), press F5. Hit it a couple of times if you're not sure how this works. Your computer will boot straight into DOS 7. Type this command at the keyboard: MOVE WINDOWS WINOTHER When your PC finishes doing what you asked, type this command: MOVE WINBACK WINDOWS When the PC is done, hold down all three of these keys -- Ctrl, Alt and Delete -- to reboot the computer. It will boot up in the other version of Windows. If the other installation was really botched and you want to get rid of it, wait a day or so while running the alternate installation of Windows to make sure everything is OK. Then drag the WINOTHER folder to the Recycle Bin while holding down the Shift key. (That tells Windows to delete the folder without sticking everything in the Recycle Bin.) Then make another copy of your Windows folder. If the other installation was still working when you switched folders, keep it where it is. When you want to switch back, follow the shutdown instructions listed above, then type these commands in DOS 7: MOVE WINDOWS WINBACK MOVE WINOTHER WINDOWS Then reboot, and you'll be back to your previous installation of Windows. Are there any cautions to observe when you have two or more versions of Windows installed on your drive? There's a big one. If you install a new program when you're running one version of Windows, the other one won't know anything about that program. The program might run just fine and it might not, depending on a couple of technical factors. You could try installing the same program twice, once under each installation of Windows, using the same program-file location each time. This works most of the time. You could also try the simple trick of copying the program's shortcut from one Windows installation to the other. That trick only works if the program itself resides outside the Windows folder -- and if it does not use an "INI" file in the Windows folder and does not use the Registry. (The Registry lives in the Windows folder, so when you change folders to switch from one installation to another you also switch Registries.) Finally, here's a technical explanation of some of the things I've described. I told you to change the swap file (in the "Virtual Memory" setting) because Windows normally puts the swap file in the Windows folder. This causes two problems. First, the swap file can't be moved while Windows is running, which means you can't copy everything in the Windows folder. (Windows stops copying as soon as it encounters the swap file.) Second, the swap file is likely to be large -- anywhere from 15 megabytes to 45 megabytes on a typical PC. You don't want two or three swap files, one in each Windows folder. I told you to copy MOVE.EXE from the place it normally is kept (the Command folder inside the Windows folder) because Windows won't find MOVE.EXE after you've executed the first of the two MOVE commands. The first time you issue the MOVE command, Windows locates MOVE.EXE in the Command folder. The second time you issue the MOVE command, the Windows folder no longer exists, so Windows can't find MOVE.EXE. (Old-timers know how to get around this, but I'm keeping this foolproof.) When you put MOVE.EXE in the root of C:, Windows finds it no matter what. A further note on MOVE: If you've used older versions of DOS, you might recall that you could rename directories by using RENDIR. That command is not included in DOS 7, the version of MS-DOS built into Windows 95. Instead, you must use MOVE. As the name indicates, MOVE will move files and folders (with some restrictions I won't get into here) both in pure DOS mode and within a DOS window. Because MOVE simply rewords the path string in the disk's file allocation table, it can also rename a folder. (To DOS, changing the name of a folder in the same path is the same as moving a folder to a different path on the same drive.) Usually, MOVE works quickly. But don't get worried if your issue a MOVE command from pure DOS mode and your PC grinds away for a long time. This can happen when the path table has been changed from a previous MOVE operation, and is normal. (Technically, booting up by the F5 method skips all disk caching, so some file and folder operations can take a long time.) One more caution: If you use this method to run Internet Explorer 3.02 in one setup and Internet Explorer 4.0 in another, be sure to follow these procedures:
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