It has always been problem when you need to reinstall your operating system again. The more problem is when you lose all your programs and need to reinstall all those programs. How do you keep track of your programs?? It has been a problem.

A way has been to to use print screen command while seeing Control Panel>Add/ Remove programs (programs and feature in Vista). But it is very complicated list. 

here is a simple way. if you are trunning windows XP or vista go to start>run and write msinfo32.exe.It will open system information window. then go to Software Enviroment. then, program groups. then you should be able to print all your currently installed programs.

good luck