Vista loophole offers free clean install to upgraders

Get a new Vista installation for the price of an upgrade.

Windows Vista is suffering from a loophole that allows users to perform a clean installation of the operating system from an upgrade DVD.

A clean installation generally performs better than an update. Upgrade versions of the operating system also are roughly 35 percent cheaper than the full versions.

Microsoft with previous operating systems provided so-called upgrade keys that allowed the software to determine that a user was eligible for a discounted upgrade. It required that users at some point during the installation inserted the installation CD for their old operating system.

Windows Vista however doesn't verify upgrade compliance this way. Instead it blocks clean installations from an upgrade disk and requires that the setup file for the upgrade is executed from inside an existing operating system.

Microsoft support however is providing information on having a clean installation on a used system, IT author Paul Thurrott claimed.

The company advises that delaying ordering the product key will result in a clean installation. After the installation is completed, users have to run the installation file again from within Windows Vista, enter the registration key and essentially upgrade the Windows Vista installation with another Vista installation.

Microsoft didn't immediately respond to a request for comment.