Although most WinXP-era programs run just fine in Vista or Win7, some include help files in an outdated format (with an .HLP file extension) that the newer Windows versions can’t open. The problem is that Vista and Win7 lack the Windows Help program (WinHlp32.exe) necessary to read the older Help files, but the good news is that you can add it yourself.

To download WinHlp32.exe, visit support.microsoft.com/kb/917607 and click the link for your version of Windows. Note that there are separate versions of the file for Vista and Win7. After you install the appropriate update (you’ll need to validate your copy of Windows to get it), your older Help files should open without a hitch.