Try this simple test. Pull the case cover and see if the lockups subside.
Why it matters. At some 2000 year model most will have never been dusted out and may have clogged or stopped cooling fans. I can safely bet that any manual with the machine doesn't cover such simple maintenance.
Compaq Presario 5000- circa 2000 1GB processor, 256 mb RAM, Windows upgraded from ME to 2000. CD/DVD/floppy with 40 GB hardrive. Locks when in operation/stalls during power up/does not complete boot cycle, but will after repeated tries.
Per earlier advice, I have upgraded windows from ME to 2000 and have run spybot and eliminated all but three spyware references; when u save/Cydoor/dyfuca. I have also run with case open to eliminate overheating - heat is not an issue.
Last night alerted to virus infection (I am using alternate computer to send this)trojan.chost which I quarantined with Norton. (May be engrained in Spybot fix it utility and innoculation)
Upgraded windows to 2000 due to multiple crashes. Computer worked well for few days-now locks intermittently when accessing any program. Ran Spybot to clean spyware. Worked better but still locks.
When restarting with power button after lock, computer will run boot sequence to DVD and CD but often will not ping the floppy in the sequence and stall. After multiple off/on with power button it will eventually complete boot cycle to floppy and start normally, only to lock up again while being used.
Looking for a solution - is it the power supply, hard drive, the CMOS battery, bad RAM etc. I am not certain anymore it is software related.