What need do you have for 32-bit? Do you have programs that don't run? hardware that doesn't have 64-bit drivers, etc?
I tried installing VB6, its not installing in Windows 7 64 bit, also C, C++, everything gives a message as "The version of the file is not compatible with the version of windows you're running. Check your computer's system information to see whether you need an X86(32 bit) or X64(64 bit) version of the program, and then contact the software publisher."
But for C & C++ I've installed DosBox, it works.
Can we go for a dual boot system?