you dont have to reinstall windows. 296.10 is known to be buggy. I and many other people have experience the same or different problems with the latest wqhl version of nividia. Best way is to downgrade to a more stable version of nividia. I personally am using 295.73.
I was using the latest drivers of nvidia until last week when i upgraded my GPU to an AMD Radeon HD 6850 so now i'm not using nvidia drivers