Why can't Vista 64 bit view Vista 32 bit apps?

Technically, it should. When you install a 32-bit application it puts it into the Program Files (x86) folder so it can properly “Emulate” 32-bit processing with that program. Now given that some programs weren’t developed to understand this fact sometimes a program can be looking for the files in (Program Files) and not in (Program Files (x86)). I remember iTunes was like that for a while. The work around that fixed it for me was to create a dummy folder in your regular (Program Files) folder and point it to your x86 folder.

here’s a link that shows how you do that.

Now I’m not sure if this is even the problem (Apple eventually fixed iTunes to work without doing this) But maybe if you told us what program you were trying to run… we could help better.