Microsoft says some Windows PCs get 'Black Screen'

SEATTLE (AP) — Microsoft Corp. says it's not to blame for a problem that is causing a "limited" number of Windows computers to boot up to a blank black screen.

The problem is cropping up on computers running the new Windows 7 software as well as Windows XP and Vista.

Microsoft says its customer service department doesn't consider the black screen problem a "broad customer issue." It hasn't identified the problem but says some malicious programs on the Internet are known to cause black screens.

A British security company called Prevx says 50,000 people have downloaded a tool it offers to fix the problem.