It's explained at http://download.microsoft.com/download/3/0/a/30ad3570-a12f-42f2-848b-138952c74a60/vfpcom.htm :
"The setup prompts you for the location of your Visual FoxPro 8.0 directory. If you do not have Visual FoxPro 8.0 installed, you should change the install location to your Visual FoxPro 6.0 directory".

So if you've VFP7 only, you're out of luck. <bg>

>At http://www.microsoft.com/downloads/release.asp?releaseid=33988
>
>

>The setup prompts you for the location of your Visual FoxPro 8.0 directory. If
>you do not have Visual FoxPro 8.0 installed, you should change the install
>location to your Visual FoxPro 8.0 directory.
>
>

>
>Perhaps it is because english is not my native language, but, I can't understand!, if I don't have VFP8, i should change to what!!?? :-D