Apple Application Support not found iTunes 9

I have tried everything to fix this problem, but everytime I download iTunes 9, I always end up with an error about Apple Application Support not found.
I've tried deleting iTunes and installing it again several times. I've restarted my computer, delete, reinstall, everything. I downloaded different versions of iTunes 9, but they all end up with the same error of not being able to find Apple Application Support.I've tried the WinRAR option to separately download the Application Support, but that failed too.
I run Vista 64 bit (and yes, I did download the 64 bit version)
Before, I think I had iTunes 9.0.2 and I upgraded it to 9.2 and it didn't work. Now I can't reinstall 9.0.2. And I can't use anything lower than iTunes 9 because it won't work with my iTouch.