You can also run the program in XP or Vista mode and there are shims for programs to patch them if they are not 64bit compatible.
I've been running W7 for over a year but have only had the 64bit Enterprise version for about a month. I have a 15 yr old Euchre (card game) program that did not run until I learned about running programs in "compatibility" mode. No guarantee it will work though, sorry.