[1337pr0]

Try these, in order:

• Un-install SA:MP, make sure everything SA:MP has been removed. Then re-install.
• Try re-installing the game from the disc, and remember to downgrade to v1.0 afterwards.
• Update video drivers, even try uninstalling your video drivers and using the Windows ones (Temporarily, of course).
• Re-install Windows.
• Buy a new pc!

If you can't be bothered with some of the steps, just skip to step 5 :/