This is a pretty urgent thing to report because it could damage or potentially completely ruin your video card if it’s ignored. The latest NVIDIA drivers, 196.75-WHQL released on March 2nd, 2010 are causing issues with the video card fan control while playing Blizzard (and other) games. This is caused by the Automatic Fan Speed feature being broken in the latest drivers.

The games included are: World of Warcraft, StarCraft II Beta and Warcraft III. If you play any of these games, you’ll want to roll your drivers back to earlier versions until this is fixed, unless you want to replace a video card within the next few days.

To find out what version drivers you’re using:

- Right-click on your desktop
- Click NVIDIA Control Panel
- When the Control Panel opens, in the bottom left corner there should be a “System Information” link; click this
- Your Driver version should be in the Details portion

Windows XP: http://www.nvidia.co…96.21_whql.html
Windows XP 64-bit: http://www.nvidia.co…96.21_whql.html
Windows Vista/7 32-bit: http://www.nvidia.co…96.21_whql.html
Windows Vista/7 64-bit: http://www.nvidia.co…96.21_whql.html

More information can be found on threads such as these:
http://forums.nvidia…howtopic=161525
http://forums.nvidia…howtopic=161503

Source: http://wow.curse.com/articles/wow-en-news/690242.aspx