Explorer Stops Working.

My friend is facing this problem since yesterday.When he turns his pc on,after the login screen he get's the following dialogue box :

"explorer.exe has stopped working".

Then everything disappears from his desktop and never come back.

He can't do anything.The start menu also disappears. The dialogue box shows up just 2/3 seconds after the logon screen.

Any solution?

I'd try using a restore point to go back to a date/time prior to the problem first appearing. Your friend might have to do this from Safe Mode by accessing Advanced Boot Options.

http://www.sevenforums.com/tutorials/666-advanced-boot-options.html

http://www.sevenforums.com/tutorials/700-system-restore.html

If this doesn't correct the issue I'd try running a system file checker scan from an elevated command prompt (option two, this tutorial.) If problems are found run the scan 3 times rebooting in between each scan. May also have to do this from Safe Mode.

http://www.sevenforums.com/tutorials/1538-sfc-scannow-command-system-file-checker.html

Your friend could also try these troubleshooting steps prepared by one of the Forum experts.

http://www.sevenforums.com/tutorials/220165-troubleshooting-steps-windows-7-a.html