restart, freeze, programs crash

ok I running on windows XP. Recently my computer has been doing some funky stuff. It randomly restarts, programs randomly crash, computer randomly freezes....

I've done scan with AVG, Tend Micro housecall, spybot, adaware, hijack this, ccleaner, regscrub, and cwshredder... so I know it's not a virus/spyware issue.
My computer is a tad bit dusty but nothing else has changed since this started happening.

Can anyone help me out? Thanks.

Edit: oh yeah.. C:/ opens on startup every time.. idk what that's about.. I could most likely fix that myself but that's not something I'm worried about.

I think several other things need doing here
1: another online scan www.commandondemand.com
2: A more powerfull scanner for spyware Ewido or Counterspy
Also maybe a hidden revealer like F-secure Blacklight
3: Test the memory sticks 1 at a time with goldmem
www.goldmemory.cz
4 Check temperatures

neither one of those sites are working for me.

http://www.commandondemand.com/eval/cod/index.htm
http://www.goldmemory.cz/

figured out the problem I think.. I had different brands of memory and after time they decided not to like each other anymore... I can put either 256meg stick in and they'll work fine but I'll get constant errors and restarts when they are both in there... but now I have another problem.

When I moved to Oklahoma 11 months ago, my onboard sound stopped working. The computer said everything was working fine but there was no sound. I went through 3 or 4 sets of drivers including my originals so I know it wasn't that. I figured it was broked so I bought a PCI card. A soundblaster from Wal-Mart.

After about a month it screws up and anytime the driver is enabled, the computer freezes. So I get rid of that piece of **** and get a new A-open Cobra from a reseller computer shop in town and it stops working after a day when I was switching my headphones to speakers and the card wiggled a tiny bit (I have no case) and the computer froze and when I started it back up I was having the same problem as my onboard sound.

Now I guess it's either bad luck or my motherboard but I'd like you guys opinions to help me figure it out.

You have no case?? I get a picture of everything just laying there and you pick up cd rom to access CD`s. I guess no cooling problems?? But I can see why problems with pci cards.They need to be rock steady to plug accessories
in to. IE: Speakers, Cat 5 jack, Monitor, usb, serial port, list goes on. :rolleyes: