The 560 is not a light load. The clue is the driver. When the driver is installed, the GPU does pull more power.
While http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-560ti/specifications pegs TDP at 210, there are real world measurements of just over 260 Watts so your PSU should be a single rail unit of about 550 Watts minimum.
My pc keeps on restarting at welcome screen ........i tried several things even formatted os....and then i noticed that whenever i install my gpu driver only then problem starts...safe mode works too......i dont know whats happening up till now the driver was working fine.....even so i tried old versions but no results.......and when i uninstall the driver pc starts up.....
My config is
I5 3570. 3.10ghz
8gb ram
Asus Gtx 560 1g

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