Windows XP auto reboot.

Actually I am setting up a new computer, or rather I am upgrading my boy's PC as I had earlier posted with a problem of continuous restarting while booting into Win XP. I was advised replacing the PSU which I did but even after that the reboot problem continues. So instead of get spoon-fed I thought of doing something on my own to be able to report the problem better. Here is what I did to check by repeating more or less the same actions as originally when I had faced the issue:

1. To remind, the motherboard is Gigabyte GA-8I865GME. The intel processor is P4 2.4 GHz (second hand, but installed fresh after cleaning and applying thermal paste).

2. I changed a bare minimum settings in BIOS.

3. I installed a fresh version of windows after formatting the partition followed by upgrading to Win XP SP2 and then to Win XP SP3.

4. I then ran the CD containing the chipset drivers from Gigabyte and upgraded the BIOS using the BIOS utility of Gigabyte. It did all right.

5. Then I installed the drivers for the Linksys USB Wireless Adaptor WUSB54G and connected it to a USB port as every time. I logged on to my wireless network and found internet working perfectly.

6. I downloaded the latest nvidia driver from the website and installed it (GE Force 4 MX 4000 chipset on XFX AGP video card).

7. I tried Windows Updates but after a few of them, the last few updates failed to install. This included IE7.

8. And it started...reboot after reboot...till I disconnected the USB wireless adaptor when the reboot suddently stopped.

9. To catch the culprit, I unchecked "Startup & Recovery -> Settings -> System Failure -> Automatically restart" and plugged in the USB Wireless Adaptor and lo behold I got a blue screen (not BSOD) with the following details:

"A problem has been detected and windows has been shut down to prevent damage to your computer. If this is the first time you've seen this stop error screen, restart your computer. If this screen appears again, follow these steps:

Check to be sure you have adequate disk space. If a driver is identified in the Stop message, disable the driver or check with the manufacturer for driver updates. Thy changing video adapters.

Check with your hardware vendor for any bios updates. Disable BIOS memory options such as caching or shadowing. If you need to use Safe Mode to remove or disable components, restart your computer, press F8 to select Advanced Startup Options, and then select Safe Mode.

Technical information:

***STOP: 0X0000007E (0XC0000005, 0XB406AC19, 0XB66F1B70, 0XB66F186C)

*** rt2500usb.sys - Address B406AC19 base at B405C000, DateStamp 425cd8e1.

Beginning dump of physical memory
Physical memory dump complete."

BTW, the driver rt2500usb.sys is the wireless USB driver. There are no upgrades available so doubting the hardware I changed the adaptor (I have a few of them) but same issue again. I do remember now that my boy used to complain on the old machine that he would suddenly find no internet available for some reason. So the problem could be a driver issue or some conflict.

Any help or suggestions? Could it be the video card clashing with the USB wireless adaptor?