I was writting a word document and the computer stopped respoding. The screen went black after a couple minutes. I couldn't get it to boot up and was running on battery power at the time so I went and plugged it in. Then I saw dark lines running down the streen so I pushed the power button and the semi-black screen came back. So I pushed the power button again and it rembooted and is running fine. Word also backed up my document for me. I wanna know what's going on with this computer though. This is the 2nd time it's done this. The first time it booted back up.