Reinstalling Windows 7 operating system is fairly a simple job. You prepare a bootable media, boot using the bootable media, select language and keyboard, accept license agreement, enter the product key, and select a partition to begin installing Windows.

The problem with this traditional procedure is that you need to enter the product key. This becomes a bit more complicated if you have lost your Windows 7 DVD box on which license key is printed or if you have deleted the mail containing your product key for Windows 7.

While there are plenty of applications out there to recover Windows 7 product key, including a free tool to recover Windows 7 product without booting into Windows 7, wouldn’t it be good if it was possible to legally re-install Windows 7 without entering the product key?

The beauty of Windows 7 and one of the hidden features of Windows 7 is that this version of Windows can be re-installed on the same PC without having to enter the product key, legally. In other words, if your Windows 7 PC is working and bootable, you can re-install Windows 7 without a product key without the help of third-party tools provided that you have a Windows 7 installation DVD.

Note that you must use Windows 7 installation DVD as a bootable media as a bootable Windows 7 USB doesn’t help in this method.

Things you need to know before beginning to reinstall Windows 7 using this method

This guide is helpful for those who have a Windows 7 DVD but not the product key.

Your Windows 7 PC must be bootable and your PC must have an optical drive (DVD drive).

Your PC must have at least 16 GB (for 32-bit) and 20 GB (for 64-bit) of free space on your Windows 7 drive (the drive where Windows 7 is currently installed). If there is no sufficient space, you need to free up some space by disabling hibernation, uninstalling programs, emptying Recycle Bin, or running disk clean up utility.

After performing reinstallation, you’ll need to manually install all applications all over again, meaning you will lose all installed applications during the reinstallation.

Re-installing Windows 7 without the license key

Step 1: Turn on your PC and boot into Windows 7. Make sure you have above mentioned free space before continuing further.

Step 2: Navigate to Start menu, click on Control Panel to open the same, change the View to Small icons, and then click on Recovery to open Recovery window.

Step 3: Here, under System Restore section, click on the option labelled Advanced recovery methods.

Step 4: In this window, you’ll see two options:

Use a system image you created earlier to recover your computer

Reinstall Windows (requires Windows installation disc)

While the first option lets you restore a system image, the second option lets you reinstall Windows OS without having to enter the product key. Simply select the second option titled Reinstall Windows and then press Enter key.

Step 5: Click on the Yes button when you see a dialog asking “Do you have a Windows installation disc?”

Step 6: The following screen warns you to back up your important data before reinstalling Windows. Even we recommend you backup all important data but since we’re not going to delete existing files and folders located in Windows 7 drive, you don’t necessarily need to backup data.

Simply click Skip button to continue.

For those who’re curious, in this method, Windows installer simply moves all files and folders located currently in the Windows drive to a folder named Windows.old on the same drive. And once reinstallation is done, it even allows you recover those files and folders but not applications from the Windows.old folder.

Step 7: Finally, insert your Windows 7 DVD into the drive before clicking the Restart button.

NOTE: You may need to make necessary changes to the BIOS/UEFI to allow booting from DVD.

Step 8: After booting from Windows 7 DVD, you’ll see System Recovery Options dialog where you need to select a keyboard input method. Select a input method and then click Next button to continue.

Step 9: When you see a dialog with “Are you sure you want to reinstall Windows?” message, simply click on the Yes button. Next, you will see “Do you have a Windows installation disc” message, for which, you need to click the Yes button, since you already have inserted the right disc.

Step 10: That’s it! Windows setup will start and begin reinstalling Windows. Once installation is done, you’ll see options to create user account, select time zone, and update settings. You won’t be asked to enter the product key.

Finally, after completing the reinstallation, you can navigate to Windows 7 installed drive, and then open up Windows.old folder to move all important data from the old installation to the new one.

And if you did perform a backup, you can click on Restore my files button when you see the Recovery dialog on your desktop.

Step 11: Now that Windows reinstallation is done and you have all your data, it’s time to activate Windows. Simply open System Properties using Windows + Pause/Break key or right-clicking on Computer icon and then clicking Properties, scroll down, click Activate Windows to activate your Windows 7. In other words, you don’t need to enter the product key. Yes, you don’t need to type the product key!

That’s all. Good luck!