pc keeps restarting!!!!

[sckitz]

hello guys new to the forum and i have a question for you guys and hopefully some one can help me get to the end of this problem.

Pc keeps restarting on boot like it will start to boot then when the windows screen gets done loading it will just restart and also i am hearing a difrent loud noise that is no usual comeing form my tower and after a while of restarting some times i can not even get this thing to turn on so i let it sit or some times if i switch the outlet it will work only to do the same thing some times i can get the screen and try load in safe mode or from last know configuraiton but it still restarts
some body told me i prolly have a virus and need to re do it but the problem is i dont have a windows xp disk but i have the code on the lil green paper stuck to the side of my pc but unfortionily i dont no have the disk or back up disk avaible or can i get hold of the person who might have one but i have the key so can some one please let me no were i can maybe download or i can just burn copy and use my same old key code

if any one has any help or questions to help get to the end of this problem please DO

I AM RUNNING XP IN IT SO I WOULD NEED COPY OF XP DISK

 

[Katmandu]

Disable your Anti-Virus at Startup. Reboot and then reset your Anti-Virus.

 

[EricB]

Right click My Computer and click on Properties > Advanced > Start Up & Recovery Settings and uncheck "Automatically Restart

tell us the error code

 

[korky122]

have you ever opened up your case or cleaned out your case lately. maby your cpu is overheating. check the temps in the bios. usually hit (del) on startup.

 

[lbrusso]

Dell and HP MBs have problems with leaking caps and will cause intermittent restarts with the "Recovered from a serieous fault" message if they are coupled with an Intel processor. I think the P4s have a special handling IRQ for hardware errors. If all else fails, try a different motherboard.