Computer won't go to BIOS & shuts down

[Fishinghat]

Hello,
My HP desktop Pavilion M9000 with an Intel Core 2 processor on a 1P1BL-LB motherboard won't go to the BIOS, but turns off three seconds after I plug it in. I have to unplug it, wait 10 seconds, then replug. It powers up but turns off after three seconds.

 

[hosereh]

Hey there , what was the happenings before this problem happened? Like a thunderstorm , Overclocking , did you open the case and fiddle around....did the PC get knocked over and the such.For the time being if you know how , clear the CMOS and try to boot.

 

[Fishinghat]

HoserEh, it's a little complicated. First, I'm getting old and my memory isn't what it use to be. It ran fine before it started to stall and slow down (I think), so I rebooted. Then Vista said I had an error (can't remember which one), so I rebooted and Vista reinstalled itself, removing everything but the OS. I thought it was a hard drive failure, so I bought a new drive and a copy of Windows 7, figuring I'd just start off with a new drive and new OS. I installed the new drive and went to change the BIOS to boot from the DVD when it wouldn't even power up. I reinstalled the old hard drive, no change. I removed the BISO battery and reinstalled, and now it won't even power up at all.