I installed skyrim on pc on the launch date, and I played up to 4 months ago without any problems. A week ago I decided to go back to playing, and I bought the 3 expansions on Steam. Since I started playing, I continue to have problems. The game is extremely jerky. I set the quality to "Low" (being a problem in that game as an archer and I can not see distant enemies), but still continues to go in spurts, and the screen is crossed by black bands transparent as big as half of the screen, cut by white lines. Many times it happens that crashes and I restart the pc, with the appearance of a blue screen. How can I do?(Sorry for my english)

Go into System Settings and turn off the auto-restart on System Error. Next time you get the BSoD, copy the error message down verbatim as the message may help track down the issue.