Posted 07 June 2010 - 01:30 PM
I would try these simple steps...
1. While the system is booting, continuously hit the f8 key. Once the menu screen comes up, select "Disable automatic restart". then reboot. The reason for doing this is because you might be getting the blue screen of death, however, sometimes the bsod will appear and then reboot the computer so quickly you do not notice it... hence why you disable it from rebooting =]
2. if you have a bsod, give us the STOP error codes
3. if you do or do not have a bsod, try entering safe mode (which can be found on the same menu as the disable auto restart). If the computer gets into safe mode without problems, I doubt that a OS reinstall is necessary.
I would also check your bios settings... make sure the system is booting to the correct drive. Also, you might test the hdd for errors using UBCD.
If you are unable to get into safe mode, and are getting a bsod... you will need to reload the OS.