As tank mentioned, it would help if you told us what software you're trying to use.
Have you actually tried to install and run it? If not, then try it to see if it works - most 32-bit programs work just fine in 64-bit Windows.
If you have tried to install and run it, where did the problem occur - installing the software or (after a successful installation) running it?
There are two main ways to get incompatible 32-bit software to run:
-> Right-click on the ".exe" file for the program, select the "Compatibility" tab and try changing some of the compatibility options. Try this first as it's the easiest.
-> If you have the Pro or Ultimate versions Download and install "Virtual XP Mode" which lets you run a copy of Windows XP inside your Windows 7 system.