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Extend Activation Period in Windows Vista
http://www.vistaarticles.com/articles/325/1/Extend-Activation-Period-in-Windows-Vista
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Published on 02/15/2007
 
Extend Activation Period in Windows Vista

Extend Activation Period in Windows Vista

Run slmgr -rearm to get 30 days.

You can do this a maximum of three times before Microsoft blocks further extensions.