There are many tips on the internet on a trick that can extend the Windows Vista trial for 3 months (http://www.tipstrs.com/tip/287/extend-your-windows-vista-trial). But now there is a trick that allows you to extend the Windows Vista trial indefinitely. That's right, you can get free Vista forever. Here's how.

1) First, you need a machine that is running the Windows Vista trial. Open the registry editor tool. You can do this by going to Start and typing regedit.

2) On the left side of the registry editor, navigat to the following section: HKEY_LOCAL_MACHINE + SOFTWARE + Microsoft + Windows NT + CurrentVersion + SL.

3) On the right side, look for the registry key called SkipRearm. Double click on this value and change the value from 00000000 to 00000001.

4) Save your changes and close the registry editor.

5) Type cmd in the Start menu search box, and then hit the shortcut Ctrl+Shift+Enter to launch it in admin mode.

6) At the command prompt, run this command: slmgr -rearm

Windows will spin its wheels for a while and then tell you that you need to reboot. Once you reboot, your trial will be back to having 30 days left. As your trial runs down, you can repeat steps 5 and 6 above and this will restart your Windows Vista trial to 30 days. Because of the registry edit changes, you can do this as many times as you like.