How to troubleshoot DPC issues!

[jamesbond007]

Hey guys! I need some major help. My system has been acting screwy lately and I haven't had any hardware changes for quite some time.

Symptoms:

• Sound/Video skips

• Mouse is jerky/jumpy

• Anything that uses the HDD (say a constant load) is broken up or interrupted. Instead of a constant activity light, it blinks when the DPC issue hits.

The past month or so has been really strange. I don't have any spyware/viruses - I can assure you that. I'm a KAV6 user and am cautious about my computer habits.

When I view the task manager, the system idle process says 98% or so, with minimal CPU going towards actual programs yet the CPU usage hovers ~30%. I have used Sysinternals Process Explorer to see that the cause/source seems to be a DPC or Deferred Procedure Call. Reading online, it seems it is usually driver related. I have updated to the latest sound, video, network, etc drivers to the best of my abilities.

I have no idea how else to fix this other than by giving the drive a clean format. I have had this OS on here for almost 2 years now and there's a lot of customizations/settings that I would lose if I did format. I'm one of those who believes that formatting is not fixing the issue, but giving in to the problem and starting over only to later find that it could arise again and I'd be in the same boat.

Specs:
WinXP Pro/SP2
Dell XPS Gen4
P4 3.4 w/HT on
2GB DDR2
Promise RAID card with 2 WD RE320GB drives (RAID1)
Onboard Intel RAID with 2 ST 160GB drives (RAID1)
Audigy 2 ZS
Linksys WMP54G wireless card
nVIDIA 6800 NU 256MB PCIE

I can't think of anything else hardware wise that would be relevant to the situation, but if you have a clue, let me know and I'll post it. I desperately need consistent and accurate mouse control because I process a lot of photos on this machine and a steady hand/mouse is needed!

Thanks in advance for any insight to my issue,
~Travis

 

[Seekermeister]

I had not heard of a DPC until now, so I would have little help to offer. But a quick Google indicated that it is a software interrupt of a lower priority. I'm guessing that what this means is that some program or driver is not functioning properly. Considering all that you said, I imagine that you have already done so, but have you gone into MSCONFIG and disabled everything that is set to start at bootup? Have you opened the Task Manager and ended all but essential processes? Did the problem continue with these steps taken? If not, then you would simply need to reenable these one at a time, until you found the one that is the problem. If the problem did continue with these shutdown, I really don't have any idea of what to do.

 

[jamesbond007]

Seekermeister, thanks for the reply. I have ended most startup processes in an attempt to see what is going on. I haven't gone to the extent of disabling stuff like my APC Power management software or my bluetooth hardware/software, but I have done simple/non-essential processes like ipod-related stuff and a few Roxio things. In all of my attempts and a few late nights, I haven't been able to yet pin-point the culprit program or driver. I guess it is news to me that an actual software program may be causing it, but considering it doesn't show any program task in the task manager as taking up the CPU power, it makes it incredibly hard to track down.

The thing is that I should have mentioned last night is that it is very random. I can go weeks at a time usually without having it bother me or I can have it for a day straight! It is just deathly annoying to deal with, but I am running out of ideas. I can be surfing the web or working on my images and then the mouse will start jerking and my sound may skip if I have a song playing in the background. To add to the confusion, I can sometimes, but rarely, reboot and it will go away for a long time. Disabling some of the services and such while it is happening has had no effect on the issue.

Bump for more input!

 

[jamesbond007]

bedtime bump!

 

[jamesbond007]

bump

 

[Smilin]

bios + driver updates FTW.

A DPC is a quick way for a driver to handle an interrupt then get out of the way. Example: NIC driver will run enough code to get some data copied out of the buffer (so more can come in) but defer any additional work on that data until it's turn comes up in the queue of other deferred procedures. It lets the IRQL get back down quickly after an Interrupt so things can get done.

Short of some heavy debugging you can't solve this without some guesses. Driver updates are the best guesses. When I say "driver" it may not always be a device driver. CD Burning software, antivirus and others all use drivers as well.

Start by running msinfo32, goto Software environment, signed drivers. Ignore the legacys, but look down the list of unsigned drivers and see if you can find updates.

 

[jamesbond007]

Smilin, thanks for the reply! I think I will endure the pain until the semester is done and will consider 'risking' my system's state when Christmas vacation hits. I have updated a BIOS before on other motherboards, which in turn rendered WinXP unbootable. I can't risk that right now, so I will do it after I've backed things up.

As far as software goes, I will surely check for updated software drivers. Alchol 120, Roxio, Acronis, etc.

The thing that kills me is that it's so random. It hasn't done it since the night I posted this thread! Maybe my computer is monitoring me and testing my limits.

Thanks for the help!