You're running some godawful pirated version of Vista. In light of this I'll still attempt to help you, but if this doesn't help you're on your own. I'd suggest a reinstall of some proper version of Windows, preferably 7 (you've certainly got enough RAM to do so).
Please install the following:
Graphics driver
Audio driver
Chipset driver (uncheck Display Driver during the setup process since you will be installing a newer version already, and do not install the nVidia nForce Network Access Manager when prompted)
Latest patch of MTA:SA
Latest DirectX runtimes