I never know what it's doing at 100% CPU
July 2, 2010 6:57 AM   Subscribe

Almost every program causes my computer to launch into some kind of super-intensive CPU cycles, clocking 100% for about 30 seconds or so before I can use said program. Happens with almost every program with any girth to it -- not Notepad, but definitely does it for Acrobat, Firefox, Word, etc.

Here is my hardware summary:
Dell Model 0RY007, Intel Celeron CPU @ 2.20 GHz, 2048 MB RAM, running Windows XP SP3.

So here's what it does. Everything runs normally during regular use. According to Process Hacker, I usually run about 1.5 GB of physical memory. Then I'll start up a program -- it''s most noticeable with Acrobat since it gets opened and closed often during the day while the other programs I use generally stay open all day. The CPU monitor clocks out at 100% for at least 30 seconds, sometimes as long as a minute. I can still use the computer for the most part, but the program that's been launched cannot be used during that time.

The only other noticeable thing is when sending email attachments. I use Thunderbird 3.0.5. When I send attachments, the computer grinds to a screeching halt until the attachment and message has been sent.

I'll be happy to provide more details about my computer, programs, etc, if it will help. I'm normally a very computer-savvy guy and I can diagnose problems with ease. I took my A+ certification class and everything, but I can't seem to get over this. Thanks.
posted by chitlin to Computers & Internet (16 answers total) 6 users marked this as a favorite
I've seen this happen when there's too much dust inside the PC. The dust prevents the heatsink and fan from properly dissipating the heat, causing everything to to slow down. It could be any number of other factors, but I suggest giving the insides a once-over with some compressed air and/or a vacuum cleaner.
posted by griphus at 7:03 AM on July 2, 2010 [1 favorite]

n'thing the suggestion to blow out the dust bunnies.
Have you swept for malware? I use Spybot, Ad-Aware, and AVG Free.
How much free space do you have on your hard drive? Once you get below about 15% free space, the computer really has to juggle to get anything done.
Have you deleted the contents of your browser cache?
Have you run Disk Cleanup?
Is your hard drive fragmented?
How large is your page file? I like to set it manually to 1.5x the recommended size. Ideally, you want to install a second hard drive in the computer and put the page file there, and not on the system disk.
posted by Multicellular Exothermic at 7:18 AM on July 2, 2010 [1 favorite]

What's using 100% of CPU when things go bad? When I've had trouble like this, I've used Process Explorer to find some weird system process that doesn't even show up in the task manager is the one using all my CPU. Usually it shows up as svchost.exe and you have to look under it to see what code is running. I've never used Process Hacker but it seems similar; can you sort by CPU and report what's running?

The behaviour witih sending attachments makes me think it's antivirus software. Try temporarily disabling all antivirus, do you still have the problem?
posted by Nelson at 7:21 AM on July 2, 2010

Your HD drivers are experiencing problems, which leads XP/onwards to revert back to... argh, I forget the fall-back driver but it's terrible. You've got hardware issues and should take that thing into the shop asap.
posted by unixrat at 7:51 AM on July 2, 2010

"Spybot, Ad-Aware, and AVG Free"

This is a somewhat outdated recommendation. Microsoft Security Essentials and Malwarebytes tend to do a much better job these days, for free.

I would also assert some kind of problem with your hard drive as the likely culprit. You might want to run some kind of diagnostic on that. I'd make a software recommendation but the only stuff I use wouldn't be available to you.
posted by Phyltre at 8:14 AM on July 2, 2010

I wonder... if DMA became disabled.
This link, http://winhlp.com/node/10, may be of help.
posted by tmt at 8:14 AM on July 2, 2010

Could be dust. Modern processors have some kind of thermal shutdown which throttles performance terribly when overheating. This was a consistent problem with my last laptop.

Could also be malware. You might be able to see this in the windows task manager; look at processes and sort by CPU% and CPU time (you'll have to add CPU time) and see if anything is hogging the CPU.
posted by PercussivePaul at 8:17 AM on July 2, 2010

If you go to the Dell support site and go to the Drivers and Downloads page, you can look up your machine by the asset tag number and find out whether your drivers are up to date and whether you are missing any updates.
posted by Multicellular Exothermic at 8:24 AM on July 2, 2010

On-access virus scanning has caused behavior like this for me.
posted by jquinby at 8:24 AM on July 2, 2010

On-access virus scanning has caused behavior like this for me.

Yes; I've seen instances where I hear about something like this and my gut instinct is that there is some sort of malware gumming up the system, only to take a look and find that it was an excess of protective software all running at the same time. In one case, there were 3 software firewalls, two spyware programs, and the anti-virus, along with a handful of other machine specific security apps, all running at once.

It's more likely something to do with the drivers or dust, but it's worth checking, just to make sure you aren't wasting clock-cycles on over-securing the machine as well.
posted by quin at 8:33 AM on July 2, 2010

This is a common complaint for people who use Norton AntiVirus. Switch to Microsoft Security Essentials.
posted by Chocolate Pickle at 9:37 AM on July 2, 2010

AV applications create a hash of executables they find and compare them to a database of hashes of known risks. This happens when your run an app. I guess you could have a bad AV app or some other AV related issue. I'm pretty fond of Security Essentials as a replacement of bloaty commercial AV apps. Do a full scan once its installed. Remove any malware.

If that doesn't do it I would update the BIOS and the video, chipset, and network/wireless drivers.

If that doesn't work I would just backup my files and do a fresh windows install (not a repair or in place install). You can spend many hours with all sorts of arcane settings or just do the reinstall. If the problem continues on the new install you most likely have a hardware issue like a dying drive or bad ram.
posted by damn dirty ape at 9:53 AM on July 2, 2010

Also, I would consider this a good opportunity to move up to Windows 7. XP is a malware magnet and pretty crappy by today's standards. If you're going to spend an hour doing a reinstall you might as well do it with modern software.
posted by damn dirty ape at 10:01 AM on July 2, 2010

To summarize, OP:

1. Buy a new hard drive.
2. Install the hard drive and use compressed air to blow out any dust.
3. Install Windows 7.
4. Install Microsoft Security Essentials.
5. (this is the "Profit" stage, without any preceding question marks.)

This is pretty much guaranteed to resolve any OS issues or infections, cleans out the dust, upgrades your experience, and protects you in the future. For a computer-savvy individual this is about as difficult as waking up in the morning, so the only barrier is $80 for a decent hard drive and $119 for the Windows license.
posted by Phyltre at 11:02 AM on July 2, 2010

Response by poster: OP here.

I use Avast Anti-Virus, Malwarebytes, and CCleaner on a regular basis. Already ran all of those tests and found no problems. The PC is pretty clean inside the case, but I sprayed the dust out anyway for good measure.

I use Process Hacker, and only the newly launched program uses up the CPU, not anything else that appears as malware.

I'm going to go ahead and order a new hard drive, I guess, and maybe install Windows 7 and see what happens. Thanks for all the advice!
posted by chitlin at 11:16 AM on July 2, 2010

I can't help but think that outright replacing the HDD is like using a hammer to fix the problem.

Did you already check the motherboard for bad capacitors? I've seen halting and skipping issues being caused by those many many times. Your Dell looks like it was built around the time that this was becoming a major issue.
posted by tmt at 11:40 AM on July 4, 2010

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