Nvidia's whole entire software suite is dangerous. There. That is the first and last time that I will parody a Busta Ryhmes song on this site.
Now to business. If you have the 196.75 GeForce drivers installed please uninstall them and revert back to the previous release (196.21) right away. 196.75 is so dangerous that Nvidia has pulled them from their site until they can be fixed. Here is a quote from Nvidia's driver download page:
We are aware that some customers have reported fan speed issues with the latest 196.75 WHQL drivers on NVIDIA.com. Until we can verify and root cause this issue, we recommend that customers stay with, or return to 196.21 WHQL drivers. Release 196.75 drivers have been temporarily removed from our website.