Take a look at FAQ#7891 Why has my VFP Help File stopped working? If it doesn't help try to reinstall VFP.

>Hi all,
>
>Has anyone else ran into this? It's a new one on me!
>
>I'm using VFP 6.0 (SP5) and for some reason, I can't bring up the help file (either using the F1 key or choosing any options from the help menu items)
>
>SET HELP is on
>
>The File Location for the help file (under Options) is pointing to
>c:\program files\microsoft visual studio\msdn98\98vs\1033\msdnvs98.col
>(and that file does exist.)
>
>I actually discovered the problem when the help file for one of our applications wasn't being displayed.
>
>Any ideas? (I've got two other machines here, all with the same configuration and the help files all work fine on those machines.)
>
>TIA,