There are two possible causes, either the driver installation is just a bit wacky
or the power supply is failing to deliver enough juice to the card under load.
If it's the driver we'll want to completely scrub your nvidia control panel and graphics driver then reinstall fresh.
Do not use the nvidia uninstaller, it misses a ton of stuff.
Instead use this application to do the removal. Phyxion.net - Driver Sweeper
For best results this should be done in safe mode.
Though you don't HAVE to be in safe mode to use it.
Also download the latest driver from nvidia before you start as once the drivers are removed everything on the screen will be enormous and it'll be hard to navigate until the new driver is installed again.
I suggest saving it to the desktop for ease of acces.
I can't link you to the latest available driver for that card without knowing whether you have 32bit or 64 bit windows.
You neglected to fill that out in your system information.