PC Locking with pulsing faster and slowr??

[harrillj]

Just trying to get pointed in the right direction. My kid has a PC about 8 months old that started to speed up, slow down, speed up slow down... and mixed in with thi, the PC would lock, mouse would not move, could not power down, could not shut down with task manager, could only pull the plug. By speed up and slow down, I mean it sounds like I hear the hard drive go faster for about 5 seconds, peak, and then slow down. This happened sporadically, but about 75% of the time the PC in use. Then when starting up after crashing, after about 1 minute, the system would lock. Could not do anything. What is weird is that the longer I leave it powered down, the longer the PC will run without a problem. Strange... but it almost seems it needs to cool down.

So...
I replaced the hard drive, same thing happened.
I ran MacAfee and Nortons over the PC and found no viruses.
Ran shredder and other trojan detection and remove appz
Uninstalled everything I could while still keeping the PC useful to my kids.
Yesterday I reformated the drive, and reinstalled the OS, and things ran fine for about 2 hours, but then the same problems came back. Right now I have virtually nothing installed. I was trying to install a wireless USB adapter when it locked up... which led to this forum post

Config:
Dell Optiplex GX240 - small form factor chassis
1.7 GHz P4
500 MB Ram
Windows XP Pro SP1

I don't know if this is a processor issue, a fan/cooling issue, an OS issue, a RAM issue.... Looking for some ideas so I can make some vendor contacts for help.

 

[lobadobadingdong]

the exhaust fan or psu fan on it could be going out. or the hsf could be loose. call dell tech support, act like you know absolutly nothing about computers and that the pc has a noise that seems to spin up and spin down like a fan going out and they will likely send a tech with a psu and exhaust fan (and/or hsf)