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Vista can run up to four months without needing activation

Though a command run in an administrative prompt, you can extend the grace period for running Windows Vista without needing activation to four months.

I recently wrote about how Windows Vista can be installed without a product key (legitimately) and run (legitimately) for 30 days without being reactivated. However, there's a new wrinkle to this story: a way to extend the grace period up to three more times, i.e., to run Windows Vista for up to four months without needing activation!

This particular method, which has been widely discussed on the Internet, consists of a single command run in an administrative prompt: slmgr –rearm. slmgr is a script packaged with Windows Vista that lets administrators perform different tasks with the machine's licensing information.

Using the command, admins can, among other things, add or remove product keys (handy if you need to change the key from the command line), erase the product key from the Registry so that it cannot be read and used maliciously by a third-party program (since the license key doesn't need to reside in the Registry anyway), and "reset the licensing status of the machine." This last function is what -rearm does, and you can do it up to three times.

Note: The commands take several seconds to execute, so if you run slmgr and nothing seems to happen at first, that's nothing to worry about.

Here's the obvious question: If the 120-day grace period was possible in the first place, why didn't Microsoft simply allow Vista to run for 120 days without a key from the get-go? In theory, that would have made it possible for folks to reinstall Vista every 120 days to get around ever paying for a license key (that is, if you don't mind having to scrape your data and applications and reinstall those as well every four months). But in a professional environment, this is, needless to say, seriously asking for trouble, not to mention a horrible disruption of work.

So I suspect the reason the total grace period can be extended to 120 days has something to do with the way other Microsoft products, such as SQL Server or Windows Server 2003, have trial editions that can run for 120 days before needing a full license key. Perhaps the reason for the 120-day total was so that Microsoft could have a ready-made mechanism within Vista's released-to-manufacturing (RTM) code to allow the easy "baking" of a 120-day trial version of the OS without having to change a great deal. In any event, no one with any pretenses of legitimacy should run Vista without a license key.

Final note: Apparently the Enterprise edition of Vista will not work with this function, since it's licensed from a local volume licensing key (VLK) server, and will not run for more than three days without a key. Three days is also the grace period for an "out-of-activation" machine, i.e., a Vista machine that has had its hardware modified or license tampered with in some way.

About the author: Serdar Yegulalp is editor of the Windows Power Users Newsletter, which is devoted to hints, tips, tricks, news and goodies for Windows NT, Windows 2000 and Windows XP users and administrators. He has more than 10 years of Windows experience under his belt, and contributes regularly to and

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