Unable to determine cause of problem!

Alright well I'm having some major issues with my computer and I am unsure whether this is a hardware or software problem!

Symptoms:
- Constant freezing for 2-10 seconds when navigating internet, clicking on files etc. Basically every time I go to do something.
- Extremely slow to respond to external hard drive being plugged in.
- Stuck on "Windows XP" loading screen during start up, have to hit the restart button and manually enter XP by going to 'Start with last known good configuration'.
- Need to press f1 every time I turn my computer on (figured out this was a motherboard battery problem, but if anyone knows this could cause so much trouble let me know!).
- Error message stating ANIWZCS2 each log in (D-Link drivers need to be updated)
- Slow, laggy and downright annoying!

What have I done to fix it?
I formatted! I completely reinstalled a fresh copy of Windows XP onto my hard drive.
I also took the computer apart and cleaned out every spec of dust.

So, it can't be viral, since it's only a few hours old! But it hasn't changed a bit, it's showing every problem I had before I reformatted. It's blue screened previously, but I didn't get the error message and it hasn't done it recently.

My computer:
OS: Windows XP Home Edition
MB: AMD Athlon 64 X2 Dual Core Processor 6000+ 3.11GHz
2GB Ram
510W PSU
Nvidia 8600 GT
500GB HDD
CD/DVD Rom & D-Link wireless card
2 Case fans & one mini fan atop the graphics card
I use Mozilla Firefox, as no matter what computer I'm on, Internet Explorer doesn't like loading, downloading or moving really, lol!

Windows XP is updated to Service Pack 2
8600 GT is updated to version 260.99 ( start up issues started after this installation, both times )

Any idea's? Personally I think that my graphics card is on its way out, which would explain the constant freezing, but I'm no expert and it doesn't explain why nothing else works!! I've considered my copy of windows is stupid also!

Thanks for taking the time to read and I hope someone out there has answers!

Try it with just one stick of RAM

I only have 1 stick in my computer, so I didn't remove it. I got a new HDD and installed Windows XP again, the lagging problem went away! But, there are sooooooooo many errors that come up when you install/update a new computer. If there wasn't, it would put you fine folks out of business!! lol!! Thank god for Google and GeekPolice! I'll be back tomorrow when the next error message appears!

Hi, you have to open your computer and take CPU, RAM and all cards out of Motherboard. Clean they connectors with eraser and put them back again. You have to remove dust from inside of computer and try to run it again.

If you have problems, leave them here for help.