So you cant acess the control panel or explorer and if you can reach one of those you can fix it right?
If this asumption is correct... Read on.
Restart computer...
Hit F10 I believe it is to give boot options.
Start in safemode and see if you can get it to work.
If not....
Start in DOS with command prompt.
for conrtol type in CMD
for explorer... C:
the windows should pop up automatically and you should be able to acess your control panel or explorer to fix your problem.

Your welcome.