Recently my computer has been lagging when I multi-task. When I was listening to music it would make the music lag even when I did simple things like open Firefox. So today I reinstalled windows to see if it would fix the problem and it didn't fix it. I got all the latest drivers to see if that would help but it is still lagging. But now my computer has restarted randomly twice. Both times when it came back on it said it had recovered from a serious error. One time it blamed it on my wireless device(which i don't think is true because I have been using the same device and drivers for 2 years) and the second time it just blamed it on drivers. Both times that it happened my screen just turned black and I heard my hard drives restart. I was wondering if anyone had any suggestions as to what the problem could be and how I can fix it.