To be able to use Windows 7 for an extended period of time, you must activate it. Windows Loader is an application which allows you to bypass the activation process entirely, but which is not supported by Microsoft. You can also use the “reset” command to renew your activation grace period. Note that the reset command can only be used a maximum of 3 times, thus extending your activation period to a total period of 120 days.
Steps

Step 1. Press the ⊞ Win key then type Cmd in the search bar
The Command Prompt program will appear in the search results.

Step 2. Right click on the command prompt and select Run as administrator
This will launch the command prompt app with administrator privileges.

Step 3. Enter slmg -rearm in the command line and press Enter
A script will run and after a few moments you will be prompted to restart your computer.

Step 4. Restart your computer

Step 5. Check your activation status
Right click on Computer and select Properties. This will open the window System properties. Your activation period will be reset to 30 days.
Keep in mind that this command can only be used 3 times, making a total potential activation time of 120 days
Advice
The reset command is not a permanent solution, but is a fully legal feature of Windows for Microsoft
Warnings
- Windows Loader may violate Microsoft's terms of service.
- If the Windows 7 installer you purchased needs to be activated using this method, you may have been sold pirated software.