http://www.telegraph.co.uk/technology/microsoft/6066383/Windows-7-free-for-first-120-days-says-Microsoft.html
- (Telegraph.co.uk)Computer users will be able to run Microsoft's new operating system, Windows 7, free for four months before having to purchase the product.
- Officially, the trial period lasts for 30 days, but a loophole has been found in the Windows 7 verification process that will allow computer users to "reset" this clock up to three times at the end of each 30-day period, thus extending the trial to a total of 120 days.

不曉得台灣能否適用，應該是可以的吧。