You can read:
http://support.apple.com/kb/ht2292 to see how you could disable what item may be causing this for a test run.
I am running a Gateway GT5432 computer with Windows Vista Home Premium 32-bit SP2 AMD Athlon Dual Core Processor. When booting up I receive a notification at the lower left of the screen stating that the driver is not responding. I close this with the task manager. Every shortcut on the keyboard remains functional after this is done. How do I fix this?