You didn't mention your OS, so pick the one that's appropriate from here:
Depending on the version that you have installed now (especially if it's from an OEM), you may need to uninstall your current driver before the one above will install.
im running windows 7
The link above brings you to a page with all the OS's. Just scroll down to the right one for your flavor of Win7 (32 or 64-bit).