"Have you tried the built-in ""System Restore"" function of Vista? Give that a try; reset back to a few days ago, and see if that fixes it.
If not then unfortunately there's about 1000 other 'answers', all of which would require further interrogation. I believe that interrogation would go beyond the scope of this single question, and you may want to consider taking it to someone who knows what they're doing before going too far trying to 'fix' it."
"First of all you should open up my computer and navigate to c:\users**your username**\documents, just to see if all of your data is there.
If you did find your data it means that the current profile has been damaged, the safe way to repair the problem would be to follow the instructions found here
This should correct the damaged profile and get you back up and running.
if there is no data to folder I pointed you to you can check c:\windows.old if it exists your data may be there as well.
If you do not see any data in the either folder you may wish to consult a recovery firm to attempt to recover any important lost data."
