Well what I suggest you do is attempt a driver rollback. Follow this guide and make sure you read through the first section:
How to identify a buggy device driver on Windows Vista | Vista Rewired
You can also attempt a driver upgrade. If none of these options work and you really want to repair Vista, just insert your CD and you should be able to repair it.
Might I suggest that if you have System Restore on, you can try to restore your system to an earlier date. Here's a comprehensive guide on System Restore:
Working with System Restore in Windows Vista | Vista Rewired
Let me know if you need anything.