Windows 7 - Program Files and Program Files x86?

I've noticed that the 64 bit of Windows has two Program Files folders, one with x86 on it.
What happens if I install a 64 bit program into the x86 folder? Or install a 32 bit program into Program Files?

Also - I use two partitions, on the second partition would I have to make two program files folders, one with "x86" and one without? Or can I just make a single folder called Program Files? (Or even something like just "Programs"...)

I can't answer this question.

You can install whatever you want on a partition you've made.

I have a separate partition for programs and I install everything I can on it (32 and 64 bit programs).
I haven't noticed any problems (I've used that method for about 10 years).

Nothing. The two program directories are only for organization, or to keep programs that have two version a 32-bit and 64-bit version separate, like Internet Explorer. But you can install a 32-bit program in "Program Files" and a 64-bit program in "Program Files x86" and nothing will happen the program will run the same.

Okay thanks!