k i will try that but someone suggestion this on another forum:
Now it sounds like you could be at the beginning of a failing hard drive. Constant rebooting is a sign of corrupted files which can be caused by hd problems. I have to think this way because you say there is no virus!
Get SpinRite 6.0 (costs a little bit of money), and run it at level 4 and see if it comes up with anything. Monitor the results now and then before it completes.
But before that; Chkdsk produces a report. Next time you get your desktop, do the following: Double click My Computer; right click the "C" drive; go down to Properties - Tools - Error-checking. Check off both boxes and reboot. Chkdsk will work on your hd for an hour or so.
When it completes, a reboot will occur. When you get your desktop back, do the following: Go to Control Panel - Admin Tools - Event Viewer - Application. Look for "Winlogon" on the right side near the top. Open it and read. If it shows bad spots, time for a new hd.
Now, especially run SpinRite to see if it can salvage something. This program will find more bad stuff than Chkdsk can, but can also fix a lot of the problems. It works on every single electronic bit switch on the drive.
If this also produces bad news (as you monitor the detailed Technical Log),
back up your system as soon as it is done, and get a new hd and do a restore.
wat do u think bout this sollution?