Hello:
A friend of mine used my sister's computer and downoaded a game like Tetris, from some site that I don't know the name of. Not long after the game was downloaded, then my sister began having problems with accessing programs on her PC.
When she goes into the start menu, clicks on all programs, and tries to initiate a program; then she gets the message, 'file not found' and she is unable to start any of the programs.
What do you think could be causing the problem and how in the world can she fix it?

Thank you,
Candice41

What Operating System? If XP try this site:

http://dougknox.com/

Win XP Fixes

Restore Default File Associations

-----------------------
Also considering the source of the problem I would recommend running HijackThis

Please follow the instructions HERE & then post your log in a new thread in the Spyware, Adware, Viruses and HijackThis Logs section.
(Not in this section please).