problems with dell D610 laptop

Info:

Dell Latitude D610

Pentium M 915 2.13GHz

1.5GB Ram, x300 video, 40GB HDD, Windows XP SP3

so recently i had noticed that it was running exceptionally slow compared to normal.  first thing i did was check the task manager for anything suspicious, and although i didn't see anything running that wasn't normally there it was running at 100% cpu for 24 processes.   suspecting a possible infection i scanned using both AVG and MalwareBytes and neither turned up with anything, not even a warning.  i proceeded to start dell diagnostics and boom, during the PSA in POST i get a PM Timer 1 error 1000-0235 and can't continue.  can anyone point me in the right direction as to continue troubleshooting or even a direct solution?  dell tech support has been zero help so far.