I did already one rearm.

Some better info here:

How to Rearm and Extend Free Usage (Activation Grace Period) of Windows 7 to 120 Days

1. Install Windows 7 without any product activation key.

2. After installation is completed, use the Windows 7 for 30 days and wait for the remaining days left to activate Windows counting down to 0, or almost zero.

3. When the activation grace period (or evaluation trial period) is almost expired or ended, log on to Windows 7 desktop, and open a Command Prompt window (i.e. type Cmd in Start Search and hit Enter).

4. Type any of the following commands into the command prompt, and then hit Enter:

sysprep /generalize

slmgr.vbs –rearm

rundll32 slc.dll,SLReArmWindows

slmgr /rearm

5. Reboot Windows 7 to enjoy another 30 days of free usage without worrying about activation nor even need to crack Windows 7.

6. When the activation grace period countdown timer almost running down to 0 again, repeat the ‘rearm’ trick to enjoy another 30 days of Windows 7 for free. User can run the rearm command for maximum of 3 times.

As rearm only works for 3 times, make sure the command is only been run when the 30 days countdown of evaluation period is almost expired.

I tried first 2 commands but didn't work and the third one worked.

Slimy said:

Windows 7 has the same rearm command for delaying activation as Windows Vista. It can be used up to three times, for a grand total of an extra 90 days to activate.

Full Story: How to use Windows 7 for free for 120 days, legally - Ars Technica

there is a comprehensive tutorial on this already here at Seven Forums by Brink

Wii Master 64 said:

just wondering, is this for those who don't have a product key?

https://www.sevenforums.com/tutorials...ays.html?ltr=A

All you need to know