Just like with Vista, Windows 7 will offer users a 30-day grace period before requiring a product activation. And also like Vista, the grace period can be extended up to 120 days, a Microsoft spokeswoman confirmed yesterday. To do so, users will have to "reset" the countdown timer with the familiar -rearm trick.

"You can run the -rearm trick a total of three times," said Woody Leonard, a contributing editor to Windows Secrets. "If you perform a -rearm at the end of each 3-day period, you end up with 120 days of full, unfettered Windows 7 use, without having to supply an activation key."

The -rearm trick will work with any version of Windows 7, from Basic on up to Ultimate. To extend the trial to four months, here's what you need to do:

1. Click the Start menu and select All Programs, Accessories, and right-click the Command Prompt and choose Run As Administrator.
2. Type slmgr -reamr and hit enter
3. Restart Windows 7, rinse and repeat in 30 days

That's all there is to it!