I have noticed a few threads recently where well intentioned but erroneous advice has been given, that by using System Restore lost data can be rescovered.
System Restore is very particular in what it backs up. Generally user generated data is NOT included. Basically it is the six registry files in System32/Config and each users NTUser.dat file that is backed up. Plus what MS describes as "Monitored File Extensions". Below are the links that show each category.
Registry Files click here - look closely at 'Not Restored'
The point of this post is that you must make independent backup's of your user generated files and folders. Such as jpg, mpg, doc, xls, dbx, pst and many others. Do NOT rely on System Restore as it will be a false hope.