1) Download the correct video driver package (Intel, AMD or NVidia support site as appropriate):
- must be for your EXACT graphics card version, AND
- must be for your EXACT Windows version (i.e. XP Home 32-bit)
2) Download the MAIN CHIPSET driver for your motherboard from the motherboard support site
- (EXACT motherboard AND version of Windows)
3) Install the MAIN CHIPSET driver first, then REBOOT
4) Open Add/Remove and look for any previous graphics driver software and UNINSTALL it if it exists.
5) Install the new Graphics Card software.
If this doesn't solve your problem I'll need more info:
- Motherboard model
- Windows version
- Graphics card