I'm desperate - System Interrupts (Windows 7)

I consider myself reasonably knowledgeable when it comes to computer issues, but I've hit a wall, and I'm banging my head against it.

First, the background, so you understand the situation fully.

I built a computer for my mother roughly 2 years ago, with the following specs:
- AMD Athlon X2 4200+ (AM2)
- ASRock ALiveNF7G-HD720p
- 2x 2gb DDR2-800
- 1x 500gb Hard Drive
- 1x DVD-RW drive
- 1x Floppy drive
- 450w PSU
- 480w UPS
- Mid-Tower ASUS case
- 3x 120mm fans (one came with the case)

At first, I installed Windows Vista in it because my mother prefered it (she says the games, like Solitaire, look better). Since the specs were relatively high for her (internet browsing, occasional word processing, and listening to music) I went ahead with it.

It worked fine until a few months ago when my mother started to complaint about the music stutter, the mouse cursor having trouble moving, and everything was just SLOW.

My first thought was that it might be spyware, a virus, or something like that but, as much as I tried to "clean" her PC, it always went back to do the same. Now, I know some software can't clean every little piece of spyware and viruses out, so I went for a full system format.

Installed Windows Vista, updated it with the latest Service Pack, and... lo and behold, the problem surfaced always immediately. I swear I didn't even install anything in it, it was a fresh install, only with Windows updates, and nothing more.

Knowing about Windows Vista reputation for being the worst **** up since Windows ME, I was looking forward to the release of Windows 7 this month and, as soon as it was out, I got a copy of it.

Again, I went through the process of formating my mother's PC, install Windows 7, added AVG Internet Security, Adobe Acrobat Reader 8.5, and Windows Live Messenger - that's it.

Same problem. After a random amount of time, even if no one is doing anything, the computer starts to lag horribly.

I went into the Task Manager and tried to see what could be wrong. Immediately, I've noticed that both cores were pretty much maxed out! Bouncing up and down between 70 and 90%, but the weird part is that when you went to the "Processes" tab, there was nothing using that kind of CPU.

Going back to the "Performance" tab, I clicked on "Resource Monitor" and now I had something to go on... in the new window that opens, I could see that the huge amount of CPU being used was set to something called "System Interrupts".

I've googled for it and all I could find was a TON of people having the same problem as me, but no real solution.

Some suggestion I read were:
- Update Chipset drivers.
- Update Motherboard drivers
- Update Audio/Video drivers
- Turn off HD audio

I tried everything from above, nothing worked.

- Chipset drivers from nVidia official website - check, didn't solve the issue-
- Motherboard drivers from ASRock official site - check, didn't solve the issue.
- Audio/Video is on-board, so they were updated from the above sources - check, didn't solve the issue.
- Turning off the HD audio... the only way I know how to do this is to go into the BIOS, but then the computer has no sound at all.

I'm running out of options here... :(

So, I need your help. Any help!

First of all, what are "system interrupts"? What do they do? Why do I need them? Why they go crazy at random?

Second, why it didn't happen before, when I first installed Vista? Was it a Windows update that screwed things over?

Third, and most important, is there a solution to the problem that I may have missed?

Scan for virus and malware infections as well as root kits.

If they are true system interrupts: could be CPU having problems. Temps OK? Might be memory: Memtest each stick separately.

I don't think it's viral or spyware related because, as I said, no program detected anything, and I've done fresh windows installs, after full formats.

Temps are around high forties when idle, but go into the fifties when the System Interrupts raise the 2 cores to high CPU usage.

I'll test the ram with memtest tomorrow and report back here. Thanks.

EDIT: By the way, what do you mean by "true" system interrupts? There are others that aren't true? I'm confused by that statement.

Quote:

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Originally Posted by SE_Saga

I don't think it's viral or spyware related because, as I said, no program detected anything, and I've done fresh windows installs, after full formats.

Temps are around high forties when idle, but go into the fifties when the System Interrupts raise the 2 cores to high CPU usage.

I'll test the ram with memtest tomorrow and report back here. Thanks.

EDIT: By the way, what do you mean by "true" system interrupts? There are others that aren't true? I'm confused by that statement.

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Sometimes thrown error messages aren't *the real deal* as the OS sometimes gets confused when the more nasty beasties occur.

Quote:

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Originally Posted by SE_Saga

I don't think it's viral or spyware related because, as I said, no program detected anything, and I've done fresh windows installs, after full formats.

Temps are around high forties when idle, but go into the fifties when the System Interrupts raise the 2 cores to high CPU usage.

I'll test the ram with memtest tomorrow and report back here. Thanks.

EDIT: By the way, what do you mean by "true" system interrupts? There are others that aren't true? I'm confused by that statement.

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Have you added any non-whql certified drivers?

Do you get this condition before you install any apps after the clean OS install?

Update on the situation:

I used Memtest 4.00 to test the RAM, and it passed without a single error.

As I said earlier, the problem persists even after a fresh Windows install where nothing else was installed, other than some windows updates.

Regarding the whql certified drivers, as I said, I downloaded the drivers directly from the official website so I believe they qualify, but correct me if I'm wrong.

Are there any viruses that survive a full format by staying in the boot sector of a drive, or infecting the BIOS? Could that explain the issue? If so, how do I clean it?

ICould it be anything else? Like a fried mobo? Fried CPU? PSU going dead? Defective cables? I mean, if I had extras of these things, I'd try them out, but I don't, and it's a shame if I start buying stuff only to find the problem is still there :(

My last and final resort will be to build a whole new PC from scratch... but that's an expensive solution, which I really want avoid.

Try a full hard drive format.
Make sure the system is not physically connected to a LAN or internet.
Run all of the motherboard diagnostics. They usually come on an optical disk with the board.
Run all of the built-in diagnostics in the BIOS.
Do a clean install of the OS using the original distribution DVD.
If the problem still exists, it is a hardware issue.

Disable the onboard NIC in the BIOS and use it for a couple of days without network access. It's pretty much without a doubt a hardware issue since I've seen it before myself, and every time it's been a broken network card/port.

If for some reason your Mom can't go 2-3 days without Internet access (or whatever the maximum time period is between lagging issues) spend $10 and get a separate NIC.

If the problems persist continue disabling each onboard peripheral in the BIOS and testing them out over days. Alternatively start by disabling EVERYTHING (NIC, Audio, USB, Video, Parallel, etc) and seeing if it fixes the issue. If it does then start enabling one thing at a time until the problem presents itself.

Thanks ua549 and MrDigital.

As I hinted at the end of my last post, I'm leaning towards a hardware issue as well.

I'll try the "turn everything off and see if it persists" option.

My mother won't have any music for a few days, but she can't really hear too much music right now since the Media Player starts to stutter halfway through the songs, so she'd rather wait and see if this gets fixed, I'm sure.

I'll report in a few days... thanks again.

UPDATE: As promised, here I am to report on my findings.

I went into the BIOS and turned off everything I could think of. I then tried the computer out for 48h and the problem disappeared.

I then turned on the on-board audio, and waited another 48h. Flawless.

Finally, I turned on the USB Controller option and, again, no sign of any problems for the next 48h.

Today, I turned on the "USB 2.0 Support" option... and about 2 to 3 hours after, the CPU jumped to 100% and System Interrupts is the culprit, as expected.

I still haven't turned everything on (like "USB Legacy Support" for instance) but it seems I've found the problem... my question now is, how do I fix it?

Well, turning it off works, of course, but how can I have 2.0 USB support without going into the BIOS? Is there a way to fix this other than to buy a new mobo? And while I'm at it, what could have caused this?

I haven't seen that issue before, but I really doubt it's fixable without a new motherboard. Whatever the differences are between USB1 and USB2, your motherboard doesn't like them.

The cheapest solution if you really need USB2 is to just buy a USB PCI card. They cost <$10 online.... well wait you're in Europe, but still. They are going to be a hell of a lot cheaper than trying to find a compatible motherboard. Does your Mom really need USB2?

It's really not uncommon to have different things fail on a motherboard. There's so many different things going on that you come to expect it. It's unfortunate but it's life.

Quote:

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Originally Posted by SE_Saga

UPDATE: As promised, here I am to report on my findings.

I went into the BIOS and turned off everything I could think of. I then tried the computer out for 48h and the problem disappeared.

I then turned on the on-board audio, and waited another 48h. Flawless.

Finally, I turned on the USB Controller option and, again, no sign of any problems for the next 48h.

Today, I turned on the "USB 2.0 Support" option... and about 2 to 3 hours after, the CPU jumped to 100% and System Interrupts is the culprit, as expected.

I still haven't turned everything on (like "USB Legacy Support" for instance) but it seems I've found the problem... my question now is, how do I fix it?

Well, turning it off works, of course, but how can I have 2.0 USB support without going into the BIOS? Is there a way to fix this other than to buy a new mobo? And while I'm at it, what could have caused this?

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If she has a free PCI slot available, buy a usb card and use it: http://www.newegg.com/Product/Produc...-010-_-Product cheapie, but worth a try. There are better available @ newegg.

The mobo has:

- 1 x PCI Express x16 slot
- 1 x PCI Express x1 slot
- 2 x PCI slots

All of them are empty, so shouldn't be a problem.

She has an external hard drive and wireless internet, so those are the only USB devices that would get affected. I don't think the internet will be any slower because of this (at least, I didn't notice any difference), but the transfers between the internal and external hard drives may suffer a bit... but probably nothing she'll notice too much.

Well, that's a wrap then.

I'd like to thank everyone for your patience, and suggestions.

I see now that this should probably be in Technical Support, not the OS forum, but at first I really thought it was Windows Vista and 7 who were acting up.

I'll look for a PCI USB device but, until then, she'll live with USB 1.0 :)

Have you try updating the bios?

I had the same symptoms and it has been driving me mad for months. Finally solved it with this http://support.microsoft.com/kb/976972