I m using windows 8 yoga 2 series laptop from lenovo. Recently I downloaded winzip from the winzip site. A free version. After downloading I saw that it has installed 360 protection sort of anti virus into my laptop too. Soon my laptop started to hang so I restarted it. And after booting when I entered the password screen went black. I tried restarting it. But it didn't helped. Tried to press F8 for booting into safe mode. But it won't go into safe mode too. Task manager isn't working too. Please help. it's just black there on screen.