I have this issue with one laptop and one desktop PC, both Win XP SP3.
The laptop is an early Asus machine that the system fan quit working and I can’t find a replacement. I’m not even sure I have booted that system in over a year.
The desktop PC is a Pentium D 820 PC that I built myself.
The symptoms are, I am either using the PC or waking it up from a period of no user input.
Everything crawls to a refresh, Process Explorer shows the top resource hog to be:
Interrupts 75.92% Hardware Interrupts and DPCs
(It varies from like 62% to 95% — it isn’t locked on the 76% number.)
On the desktop PC the fans all spin, I have upgraded to a new 750W power supply.
I don’t see any capicators with their tops blown off on the motherboard or any of the PCI add-on cards.
I am usually using Internet Explorer 8, but I don’t leave it up when I leave the machine.
If I reboot, either a “soft” restart or a power interruption, the problem goes away for the rest of the day and the system works wonderfully. If I leave it up, the problem will resurface in the next day or two.
One thought is that Norton Antivirus is scanning the files on an attached USB drive, but none of the Norton process are even in the top 5 when this slow-down happens. The interrups continue to happen at the same rate if I unplug the USB hard drive, and it will go into the same state in a couple of days if I boot the PC without the USB hard drive attached.
Any clue as to what causes the Interrupts?
