Microsoft Windows' infamous "Blue Screen of Death" has become synonymous with an operating system crash or freeze, but that's nothing compared with what users of pirated copies of Vista worldwide can expect from now - a black screen of darkness.

In an e-mail to a large Windows Vista OEM distributor titled "Pirated Vista - A darkness descends!", a local Microsoft representative made it quite clear what Vista pirates can expect to happen to their unlicensed installations.

A copy of this e-mail was obtained by Computerworld.

"Good Afternoon, As of this week, Microsoft have activated a function in Vista called 'Reduced Functionality'. This is a specific function in Vista which effectively disables non genuine copies of Windows. Therefore, anyone who has a pirated copy of Vista will experience:

A black screen after 1 hour of browsing
No start menu or task bar
No desktop

Please communicate this anti-piracy initiative from Microsoft to your resellers - note this function has only just been activated in Vista worldwide and therefore any issues with non genuine versions will start to arise from now onwards."

Microsoft's new tough anit-piracy move also proves the company still controls its software releases with an iron fist, but it marks the first global use of heavy-handed tactics for pirated copies of Windows.

The e-mail message also included what resembled an advertisement of the new anti-piracy initiative.

Titled "Don't let this happen to your customers", the advertisement indicates non-genuine copies of Windows Vista will lose access to key features, have limited access to updates, and thus risk attack from viruses, malware, and spyware.

"If Windows Vista is not activated with a genuine product key, your customers will experience reduced functionality," according to the ad. "The blocking of non-genuine product keys is an ongoing process, not a one-time event. To help protect honest partners and fight piracy, Microsoft will continue to block product keys that are determined to be pirated, stolen or otherwise deemed non-genuine."

The ad concludes with "Don't risk it!" and "make sure your customers always get genuine Windows Vista preinstalled".