Turn On your System
Press F8
Choose Safe Mode and Press Enter.
When desktop picture appears, press ctr+alt+del.
Goto - > File -> New Task.
type -> cmd
press enter
type cd\
cd windows
cd system32
cd restore
rstrui.exe
press enter
or Click Start -> All Programs -> Accessories -> System Tools -> System Restore.
Click Next
Choose the date when your computer was okay.
Click Next
System is Restoring.
Hope your problem is solved.
