screen(or pc)freeze

this happens when i play skyrim on windows 7 64 bit and on xp 32 bit when i am on facebook or reading news,it ocured when i tried u update to beta drivers 14.3(i did it eventually).for skyrim i have skse,lock overhaul,latest patch,all bethesda dlc and falskaar and bethesda high res texture mod.this ocurred when i had 13.12 catalyst

solved it.changed 400w psu to 530w and now it's working like a charm

Ok, I guess the capacity limit of your PSU was downscaled because it aged.