This is a driver issue.
You need to do the following:
- Download (but do not install yet) Driver Cleaner here: http://downloads.guru3d.com/download.php?det=745 on the machine you are accessing the internet with and save the application to a thumbdrive or something similar to transfer to the affected machine.
- Do the same with this (dont install yet): http://us.download.nvidia.com/Window...glish_whql.exe
- Enter safe mode (tap F8 on restart) on the affected machine.
- Disable any antivirus software.
- Go to Add and Remove Programmes and uninstall any display drivers (e.g. nVidia or ATi).
- Install Driver Cleaner (downloaded at 1) and run it for nVidia and ATi.
- Restart in safe mode again (tap F8 on start)
- Install the nVidia driver downloaded at 2.
- Restart normally (enter bios and ensure onboard video is switched off).
Post outcome. If this doesn't work, then download PC Wizard from my sig and install it in safe mode. Then go to FILE, SAVE AS and click OK. Then save the text file and copy its contents into this thread. Also post what PSU you have (make and model) - ie report what is on that sticker.