My PC is shuting down when I try to open AutoCAD

[dva94]

Hello,
My PC is shutting down as soon as I open AutoCAD program.
I have Asus m2n-mx motherboard, AMD Athlon 64 X2 Dual Core Processor, GeForce GT520 videocard, Two Hard drives-one 250 & one 500 GB. My power supply is 500 W. Any ideas ?
It runs Windows 7 ultimate.

 

[trapper]

How much ram are you running?