You can try installing the drivers from Intel. The generic drivers bundled with the Windows installation CD's usually don't have optimizations (most notably they don't have OpenGL support).
http://downloadcenter.intel.com/Prod...=2301&lang=eng
You'll have to pick your OS there. I'd give you the direct link, but I couldn't tell whether you were using the 32-bit or 64-bit version of Vista Business.
Then just grab the first download. (The second one is for developers.)