How to reset Windows 7 rearm couunter

An install of Windows 7 without an activation key allows for 30 days of usage. This can however be extended up to 120 days by using the following slmgr (Software Licensing Management Tool) command to rearm or reset the 30 day trial. slmgr /rearm (Remember to run this command, you must right click on cmd and select “Run as administrator” for this to work) However this can only be done up to 4 times. You can view the number of rearm counts by using the command which displays the current license information: slmgr /dlv

In order to reset this counter do the following:

Create a .bat file using the following commands reg load HKLM\MY_SYSTEM "%~dp0Windows\System32\config\system" reg delete HKLM\MY_SYSTEM\WPA /f reg unload HKLM\MY_SYSTEM and save it as ‘reset.bat’ to the C:\ root folder. Restart your computer, pressing F8 to get to the Advanced Boot Options. Select the option to Repair Your Computer. Select your keyboard input method. Login with your login details. In the System Recovery Options menu, select Command Prompt. Now type in C:\reset.bat. (If it says “‘C:\reset.bat’ is not a recognized as in internal or external command” message, then it may be because the  C Drive is bring used as a recovery partition. Try again using D:\reset.bat) If successfully you should get the message “The operation completed successfully”. Next reboot your machines.

After rebooting you may get a message stating that this product is not genuine. When prompted to enter a product key enter a generic windows 7 key that can be found online. Running slmgr /dlv again will confirm that the rearm count has been increased again, thereby giving you another 120 days worth of windows use.

Source: http://www.daniel-mitchell.com/blog/reset-windows-7-rearm-count/