There should be a link to System Restore in Accessories, in the Start Menu. If you cant find it, open help and support and search for it.
It guides you through the process very well, so you shouldnt need any help in doing it.
Hopefully that will work. But if it doesnt, reply back to us, and we'll try something else.
System Restore wont get rid of any changes you have made to your "My Documents" folder. It will reset the program files, and registry changes to the specified date.