PC wont boot to hard drive

[mikehombre]

Hello I have just loaded windows 7 64 bit on a brand new hard drive and had everything working and running pretty well. I also upgraded the ram to 8 gigs (made certain of all specs) All of a sudden today the tower fan started making a strange noise and then the whole PC just shut down. Ive replaced the fan but when I start my computer it beeps once (normal) displays mobo screen and displays the option to boot to disk but then doesn't boot to the hard drive. i've reset the CMOS, checked all the cables, tried plugging in old drive that still has windows xp on it.

Any insight is appreciated

mobo - gigabyte GA-P35-DS3L
CPU - INtel Core duo - quad core
Harddrive - western digital - 500 gigs

windows 7

thanks

 

[phil22]

Try fitting a new PSU, preferably one with higher output-wattage than the existing one.

 

[mikehombre]

up and running, thanks!