I am testing Windows 7 Pro on my laptop and wanted to decide if I can get by with that instead of Ultimate. Well, my time is running out and I need a couple day to backup everything before I change it. So… I need to “rearm†the activation system.
Go to the start menu, and in search box type “cmd†and hit CTL-SHIFT-ENTER to open the command prompt with elevated rights. Type this:
1: slmgr -rearm
You’ll get a popup telling you it was successful and you need to restart a few seconds later.