Severe PC slowdown. 100% CPU usage...

[LordLove]

Yo guys.

I have what appears to be a rather troublesome problem. For some reason my pc experiances severe slowdowns when in windows, and I'm left pretty baffled by it. There's a bit of history to the story though so I'll explain that first.

Origonally my PC started blue screen crashing while in windows, I'm not sure why, but it was a Kernel related error apparently. Anyway, before I had chance to fix that, the pc decided to cut out on me perminately. I took it to my local repair guy who discovered the motherboard had gone. He replaced it with a new one, and I went home and did a fresh reinstall of windows.

Sadly however this lead to another problem. The PC now began to randomly shut down - usually while running a program, especially more processor intensive ones. It wouldn't restart until I turned off the power before turning the machine back on. Also it would sometimes claim the processor was at 100% usage when it was idle. After ruling out overheating of the CPU (which seemed to stay around 47 degrees in windows acording to SIS Sandra). I assumed it must have been the power supply. I went to the shop and bought a new one and fitted it today...

Well the crashes are now gone, but low! the other problem is still here - the processor still decides it's going to be at 100% usage while doing next to nothing and won't return to normal forcing me to restart. Everything just locks up...even worse than it did before. After a restart it's fine however (until the next time it goes off on one of course). I tried running a virus scan today and it detected nothing, I also reinstalled windows again just to be sure. It's not doing this all the time - it was fine for a good few hours tonight while I wasn't using it...it just kicked in again while I was playing poker online with an mp3 running at the same.

I wonder if any of you guys have had this problem. My specs are as follows...

ATX 400W power supply (new)
ASROCK K7Upgrade - 880 Motherboard (new)
AMD 2600+ Processor (just over a year old)
512mb DDR400 Ram (just over a year old)
ATI graphics card (I forget the actual number but I think it's a 9600)
80gig Seagate SATA HD

I've installed fresh:

ATI drivers
Motherboard sound drivers
Microsoft office
Winamp
Opera and Mozilla
WinDVD
MSN Messenger

I suspect however that the problem is hardware related, but I hope it's not going to involve replacing more parts because I'm running out of money!

Hope you guys can help!

[odannyboy000]

Do you ever do any virus scans? Your computer at idle could be 100% because you have virus' working in the backround. While I was reading what you said, I first thought that your system was slow because you didn't have enough RAM, but 512MB isn't THAT bad. If I were you, though, (and I'm not) I would buy some more.

[saphalline]

100% CPU usage isn't a hardware problem. There's no way for a bad mobo, for instance, to suddenly give the CPU something to do. This is a software problem. Do you have the latest BIOS for your mobo? Do you have all the latest Windows updates? SP2 and all that? Do you have the latest VIA 4-in-1 chipset drivers? Is this system connected to the internet? If so, how is the security?

At this point, I'd recommend posting a HiJackThis! log to the security section of the forums.

[LordLove]

So you can definately rule out a cpu/ram problem? excellent.

The computer is connected to the internet via a network (it's not the gateway pc), The security is shall we say...a little lax (there isn't any!), but I've had this set up for about 2 years now without problems, and the 3 other pcs on the network aren't experiancing such problems. The Windows XP installation is SP2, and I have updated all the security stuff. There were no VIA 4-in-1 chipset drivers on the motherboard cd, so no, I haven't installed those. If I wanted to do so, where would I find the drivers...and while we're at it, what exactly do they do?

I don't know about how recent the BIOS is, and to be honest the idea of flashing the BIOS is one which freaks me out a little. I do know however that the other PC next to me is using almost exactly the same setup (same mobo, ram, HD), only with a 2600+ sempron instead of an Athlon like this one, and works fine.

So that leaves the Hijackthis log...I've never heard of one of these before, but I'll google it and see what comes up, and have a go at posting in the security forum.

Thank you guys for all your help!

[saphalline]

Your latest chipset driver (http://www.viaarena.com/default.aspx?PageID=420&OSID=1&CatID=1070) (top one). The chipset driver is responsible for making sure that all drives and devices on or connected to the mobo are properly detected by the OS (like Windows). It's very important to install these before any other driver on your system.

HiJackThis (http://www.majorgeeks.com/download3155.html) is a great tool (if you know how to use it) for detecting unwanted visitors and squatters on your system. It produces a log file that you can then copy and paste into a post (or span several posts if need be) and have the experts take a look at it.

Forget the BIOS for now. We'll cross that bridge if we need to.