I bought 2 years ago this notebook

but more and more often he just got a bluescreen if notice that that doesn't happen if i choose at the settings at the energy option "power play" that it should save my battery ... if i togle too high end the the laptop just shut down with a blue screen

i already gave my latop 3 times and they send it for always like 4 weeks away one you said everything is right second time suddenly a usb didnt work anymore and after that you change the mainboard but with no effekt to my problem  i got the news catalyst control center i hope someone know here the problem ...i got a ATI Mobility Radeon HD 4670...win7 32