Re: suddenly games are crashing/freezing
It sounds like you have Windows set to download updates automatically, which is probably the crux of your problem. You should always do manual updates of Windows because in addition to security updates, Microsoft will release its own drivers for hardware and those can cause more problems than they solve.
As far as your Outlook goes, that was probably due to another Windows update. NVIDIA and Outlook (which you really shouldn't be using anyway) are mutually exclusive programs.
Sounds like something got royally hosed somewhere, and the only thing left to do is to back up all your critical data to another hard drive or CD/DVD and do a clean Windows re-installation. That should clear everything up. Just make sure to not have Windows update itself automatically.