You simply install the program as usual. During the installation process it should default 32-bit software to the C:\Program Files (x86) directory.
Is Win 7 not allowing you to install the program? Or does it not run properly?
If it is the latter, then it could be the program is not compatible with Win 7. The only solution is to download the Windows XP Mode program from Microsoft, but that program is only compatible with Windows 7 Professional and Ultimate.