I won't comment about your list. I'll let others do that.
Tell me if you replaced all heatsink compounds in the machine and if this is an IDE drive did you try the old XP DMA fix and did you unplug all USB drives and the Optical drives for a test run?
After that I'd like to see your HIJACKTHIS log file.
bob
Computer is HP Pavilion desktop PC, running WinXP Home Edition, SP 3, with all MS updates installed. Five days ago, the system abruptly exhibited severe delays in response to all input: 15-20 second delay in responding to each mouse movement or click, and to each keyboard input. I have done each of the following:
* Ran AVG 2012 - Result: clean, no viruses found
* Downloaded and ran the latest McAfee AntiVirus - Result: clean, no viruses found
* Ran Microsoft Malicious Software Removal Tool - Nothing found
* Did a registry clean (Eusing) - removed 3,031 registry problems
* Ran Win95 Disk defrag,
* Executed a Win95 System Restore to a restore point one week before the onset,
* Ran CHKDSK from both Windows and the Command Prompt, with /f /r options, several times (results appear too briefly to read! What happened to the Windows95 CHKDSK that showed an on-screen representation of the sectors and blocks as they were scanned, along with clear results?? That was much more useful.)
* The HD is a 200-GB Seagate, so I ran SeaTools for Windows many times, with every option: DST, SMART test, Generic-Long and Fix All- Long. Every one says "Passed" with no disk problems reported.
At this point, I have to reboot the computer every 20 minutes to use it at all. By 20-30 minutes after boot-up, the performance is so bad that it's unusable. Doesn't matter what applications are run - appears to be a function of time only. What else can I try here?

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