Help with freezing/slowdown problems please

Have you tried a scan with Malwarebytes.

It could be hardware related but it kinda sounds like malware or a virus.

I have tried quick scanning with Malware Bytes with no threats found but I'll try a full scan now..

Post your system configuration.
Have you defragged the HDD lately?
Also have you looked to see what process is using the core in task manager?
Also you might try to run HDtune, check the smart, and run the tests to see if it is the HDD.

AMD Phenom II x4 955BE @ stock w/ stock cooler
Gigabyte GA-MA790FXT-UD5P mobo
EVGA GeForce GTX 260 core 216 @ stock
4GB Corsair RAM
640 GB Western Digital Black Caviar HDD
Windows XP 32bit

I have defragged the HDD recently, and I still have problems.

In task manager, it's usually just System Idle Process that's using the CPU.

And I'll come back when I have the tests done.

So the full scan turned up one infection, here's the log:

Malwarebytes' Anti-Malware 1.46
www.malwarebytes.org

Database version: 4792

Windows 5.1.2600 Service Pack 3
Internet Explorer 7.0.5730.13

10/10/2010 5:55:58 PM
mbam-log-2010-10-10 (17-55-58).txt

Scan type: Full scan (C:\|)
Objects scanned: 261076
Time elapsed: 45 minute(s), 44 second(s)

Memory Processes Infected: 0
Memory Modules Infected: 0
Registry Keys Infected: 0
Registry Values Infected: 0
Registry Data Items Infected: 0
Folders Infected: 0
Files Infected: 1

Memory Processes Infected:
(No malicious items detected)

Memory Modules Infected:
(No malicious items detected)

Registry Keys Infected:
(No malicious items detected)

Registry Values Infected:
(No malicious items detected)

Registry Data Items Infected:
(No malicious items detected)

Folders Infected:
(No malicious items detected)

Files Infected:
C:\Program Files\WeFiBar\tbWeFi.dll (Adware.NetPumper) -> Quarantined and deleted successfully.


and HDtune's error test didn't detect anything wrong with the HDD. Came back to the computer after a few hours and it hasn't frozen on me yet... if my problems were due to the malware I just removed I'll be very happy.

but if not, you'll hear from me again. >.>

Let us know how it goes.

Today I got another freeze at the log in screen.  

This is the standard checklist I usually post for diagnosing hardware issues. It applies specifically for boot issues so not all will points will be relevant to you but the basics should still apply.

This is a good guide on boot issues. Check everything on this list one at a time and double-check everything is connected correctly. Post back here when you're done and we'll go from there.

http://www.tomshardware.co.uk/forum/261145-13-read-post...

It could also be a memory issue.To test faulty RAM try using only one stick at a time and try each stick in each and every slot on the motherboard. This will rule out either bad memory or a faulty motherboard. Failing that, try removing all non-essential components and replacing each one by one to locate the faulty component. This includes everything except your motherboard, CPU and RAM.

If you've been through everything on this list and still have no luck then you're down to your motherboard, CPU and PSU. These can only really be tested by substitution - just swap each part one at a time until you find out which one is faulty. Hope this helps and post back to let us know how you get on.

Basically, it's elimination of possible factors until you find the faulty component.