The past few weeks my pc shuts down when i play music while oon games,and have now just started restarting itself after an hour or so.It have come up once that the bios needs updating.I wanted to start again by taking the computer back to factory settings,but cant remember how to do this.I no i got to press one the f keys,can anyone help me please?

No, no, no! You do NOT need a BIOS update & do NOT need to reinstall Windows. More than likely, your system is overheating. Check the temp readings in the BIOS under the PC Health menu. When's the last time you opened the case & blew the dust out of it? Your power supply may also be the problem. Overheating or simply old & tired. Another possibilty is that you installed a buggy driver or program & you have Windows configured auto-restart when there's a problem rather that displaying the error message. Turn off auto-restart. http://pcsupport.about.com/od/tipst... There's also the possibilty of infection. When's the last time you did a thorough cleaning...dumped temp files, scanned for viruses/malware/spyware, defragged, etc?

Hi thank you for your reply.I have cleaned the inside from dust,and also cleaned up my c drive and temp files and its still shutting down.I have turned off auto restart like you said and its still happening.I have backed up my system and was thiking would it be better to just do a master re set?only thing is i dont no how to do this,i have pressed the f8 key but what option do i use? please reply back to me thanks