Help pls. system keeps clicking and then rebooting itself regardless of what I am doing but is ok in

opp sys xp. I have norton, spyware blaster and super antispyware all state i have no viruses, have used ccleaner to clean. It reboots regardless of what I am doing and not to any timescale, but does not do it in safe mode..... any help would be appreciated. thank you

Help pls. system keeps clicking and then rebooting itself regardless of what I am doing but is ok in safe modecomputers

Theres more then just 1 or 2 things that could be wrong here....

1.click start and then control panel,when there click windows updates and get all windows updates that are there.Download them,install them,then reboot your pc.

2.Click on My Computor and go to Hard Drive C and right click on it,then click on properties,and click on the Disk Cleanup tab,it will then scan your HD and you will after a few minutes get a new screen appear,tick all the boxes there and then click on the more options tab,where you see the system restore tab click 'clean up' it again will take a minute or 2 but once you have all this done then we can move onto the next step.

3.Click start and then all programmes then goto Accessories there select System Tools and goto Disk Defragmenter and do a full defrag on HD C.

This should help with these issues but if they dont then as a last option i would say to do this.

4.Click on My Computor and then right click on HD C go to Properties and then select the Tools Tab,there select the Error Checking tab and and tick both boxes there.The pc will say that this drive is in use and will set your pc to check this drive when you next reboot.Click ok and then go ahead and reboot your pc,you will get a blue screen with writing whilst your pc checks and fixes your HD (this can take some time) let it do what it needs to do then it will reboot itself and come back as normal when its complete.