A trick has been posted lately at Vista.Blorge.com about installing a full version of Windows Vista from an upgrade version disc.

The instruction is:
1. Install it without the license key.
2. “Upgrade” the installation and enter the license key.

Therefore, it means that all a user has to do is install the upgrade version twice and save about $100 from buying the full version.

“The fact that the company has not taken steps to remove the upgrade trick from Vista SP1 leads us to believe that Microsoft executives knowingly support the trick,” said the Windows Secrets editorial director.

Source: Vista.Blorge.com