AMD 64 3000+ Venice Core
WD harddrive 200gig + 120gig
asus 6600GT
asus A8N-E
soundblaster audigy
2x512MB OCZ Performance ram
520W SilenX psu

I'm pretty stumped... a couple of weeks ago, my computer started to do strange things. It began to spontaniously restart seemingly at random. I tried to update drivers so I updated my chipset drivers and bios which only made things worse. My computer began to restart as soon as I saw the desktop and the blue loading screen before the desktop shows didn't last as long as normal. I ended up being able to load in safemode and I restored to a previous good configuration and the problem went away, or so I thought.
I thought the problem might be related to my virus scanning software so I uninstalled it and installed a different version of norton, which made the problem come back again. Norton recommended I clear my temp folder and delete all junk left by norton and then restart, which I did, and it worked. Once again though, only for a short while.
Basically, now my computer will load normally until it should show the desktop but then just shows a mouse and a black screen. When I restart the computer, it loads to the desktop, begins loading virus scanner etc... and then pretty much freezes in the sense that I can still move around my mouse and clickon things, but nothing happens. It seems like windows on ultra slow mode. After doing a hard restart again though, my computer works fine. Under gaming conditions and even while being on for a very long time, it never seems to restart. Here's the error I got the last two times.

BCCode : 100000d1 BCP1 : FFFF00F6 BCP2 : 00000002 BCP3 : 00000001
BCP4 : B9C4F8D4 OSVer : 5_1_2600 SP : 2_0 Product : 256_1

I've changed my settings to not automatically restart my computer when it gets and error so now I've got some STOP error codes that might help. My computer's also started crashing at times other than when the desktop is loading....

DRIVER_IRQL_NOT_LESS_OR_EQUAL

STOP: 0X000000D1 (0X61436D79, 0X00000002, 0X00000000, 0XF3DE623B)

NVTcp.sys - Address F3DE623B base at F3DE2000, DateStamp 41c24f0b

and then it crashed again with this error code....

DRIVER_IRQL_NOT_LESS_OR_EQUAL

STOP: 0X000000D1 (0XFAD000EC, 0X00000002, 0X00000001, 0XEFDC98D4)

HTTP.sys - Address EFDC98D4 base at EFDB800, Date Stamp 41672744

Im having similar problems with a PC I built from Tigerdirect.com At first I couldn't get XP to install, thought it might be hard drive so I swapped with a brand new one. Then thought it might be the soundcard so i took it out. Then I finally got XP installed but the computer randomly restarts for no apparent reason. I checked temperatures but all is good. Made sure CPU fan is properly seated. I even bought and swapped a new power supply. Nothing.

Now, try this. I took the motherboard out of the case but left it connected (power off and unplaugged obviously). Start the computer with the motherboard outside of the case on an anti static bag. VOILA! The PC worked fine which means that there must be a screw or something metal touching the motherboard somewhere in the case. Right now I am on the hunt for the problem... but try that and see what you come up with!

AMD 64 3500
Chaintech S1689 socket 939
1024 DDR2700
Geforce 5700 LE 256 MB
80 Gig Western Digital ATA
30 Gig Maxtor ATA
Windows XP Home

dzoutzidis, do you have NVidia Firewall installed? Even if you don't think so, check it. I haven't realized I have it installed until I have seen it with me very own eyes. If you do, use another one (e.g. the one built in SP2).

well, it finally did it.... my computer finally kicked the bucket.... I was trying to upsdate some drivers for my motherboard when I got the blue screen of death again. i restarted and got an error message saying that nvata.sys was missing or corrupt. That was the last straw..... thankfully I had backed everything up and emptied my 120gig hard drive onto my 200gig hard drive so I just reinstalled windows last night onto the empty smaller one. Everything seems to be working beautifully now..... just a royal pain in the ***.... thanks everybody for trying but I never could actually fix the problem and I have no idea what caused it. Just a word to the wise..... back up EVERYTHING. I'm usually pretty lucky cuz I've got either a second hard drive or a buddy on the same network as me or a portable hard drive or something like that.... but basically, always have a backup plan!

I have had the same problem,took me a few days to (I think)fix it. Actually this is how I learned about techspot. Just disable services: UPnP, SSDP and HTTP SSL (WWW Publish Services if you have it) Those are the services dependenton HTTP.SYS
Restart is safe mode, run, cmd, services.msc, etc

Alternatively regedit HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services....
look for the above services and change the Start REG_DWORD to a 4

Hope it helps