My dad's Dell started forming hundreds of lines down the screen to the extent where you couldn't see the screen. He had to get it replaced. It doesn't sound like your problem though, is it under warranty?
It might be, but I think I got what was wrong with it. I think there's something wrong with the battery, because it happens only if I'm running on power. And when I pull out the charging cable. Or it might be because of high CPU. I don't really know, I just try to avoid these things, and things seem fine with it. For now.
Thanks to everyone who tried to help though.