When installing existing (i.e., Windows XP-compatible) applications in Windows Vista, you may run into several issues. The latest is a problem with older help files supplied with such software.
Help files that use the .HLP extension are run with the program WINHLP32.EXE, but if you try to launch such a file in Vista, you'll get this warning: The Help for this program was created in Windows Help format, which was used in previous versions of Windows and it is not supported in Windows Vista.

You'll then be directed to Microsoft Knowledge Base article 917607, which describes how WINHLP32.EXE is not even shipped with Vista, inasmuch as it "no longer meets Microsoft standards." (What's even more irritating is that the 16-bit help file application is included in Vista.)

But if you do need WINHLP32.EXE, the article continues, it will be made available as a download from Microsoft after Vista is available for commercial release. Fine, except that if you're working with Vista and you need access to such help files, such explanations aren't going to be very comforting.

The good news is that there's a workaround that's easy enough. Go to a machine that's currently running XP and copy WINHLP32.EXE from the \Windows directory. (Note: For safety's sake, don't place it in Vista's own Windows directory. Instead, create a subfolder in Programs called Legacy Help (or something along those lines), and place it there.)

Right-click on a legacy help file and select Open With to associate with WINHLP32.EXE. From that point on, all legacy .HLP files should open with WINHLP32. By default, such files are opened with the "Windows Winhlp32 Stub," an application that simply pops open the explanatory text described above.

If you're building a Vista image for deployment on multiple machines, this might not be a bad default addition to such an image. . .especially if you're going to be stuck working with a lot of software that has legacy .HLP files!