9 times out of 10, you can run 32-bit programs in Windows 64-bit. There are a few that wont but I have rarely seen that. I have a couple 16-bit programs that run great in Windows 7 64-bit.
What programs are giving you issues?
Note: If you have over 4gb RAM, switching to 32-bit, you will lose access to anything over 4. That is a limitation of 32-bit OS's.