Opening Programs

Hello,

I have windows XP on my PC and recently it was attacked by some virus and I got the virus out using some anti-spiware scan.
Now, my PC wont open any program and if I click on any program it shows, exe not found, and even the internet explorer is not working on my PC, and I just cant do anything with it.
Can some one pls help me and tell me how to get my PC back to order??
I would really appreciate it alot...................thank you