In order to register and activate your copy of Windows operating system you need your product key. Without activation, you will not be able to get remote Windows support services and updates despite your system working. A Windows product key is a 25 character key unique to your PC or your off the shelf windows product.
If your Windows 7 (or earlier) computer came with a preinstalled OEM (original equipment manufacturer) version of windows, then your product key should be available on a sticker at the back of your PC, or on the inside where you plug your battery. For Windows 8 and 10, the product keys and OEM license model has changed. If you buy a Windows 8.1 or Windows 10 pre-installed computer, you will no longer see a sticker on the back or top of the machine with a product key printed on it. In the cases of Windows 8 and 10 OEMs, the original product key is embedded into the computer’s BIOS. If you bought your version of windows from a retail store, then the product key should be on a sticker inside or on top of your product cover.
Clean installing a new version of Windows will need you to re-enter your product key in order to activate Windows. If you have lost the physically available copy of your product key, or the sticker is now too old and invisible, there is a way to retrieve your previous product key that you used before upgrading or installing a new operating system. In this article, we will show you how to retrieve your product key from the old files of your previous Windows installation.
How Windows Product Keys are stored
When you activate your product, the keys are usually stored in the registry. Your Windows product key was also packed into a file in the windows folder. You can see your product key from the system properties by going to control panel > System and Security > System. The product keys are also stored in the registry hive files located in C:\Windows\System32\config\. The ‘Software’ hive includes information about Windows operating system as well as the product key.
When you clean install a new version of Windows on a partition with an existing OS, Windows creates a folder that archives your old operating system together with its program files and personal data into a folder named Windows.old. You can therefore be able to retrieve your Windows product keys using the following methods. We will assume that you haven’t deleted your Windows.old folder yet.
Method 1: Use Nirsoft ProduKey utility to view your product key
ProduKey lets you scan your system folder or a specific registry hive file to find your product keys. You can then choose to save the results as a text file. You can use this method to retrieve product keys from other hard drives too.
- Download ProduKey from here (we recommend downloading the portable zip version that you can easily use without having to install it to your system)
- Extract the .zip file or double click to open it
- Double click on the produkey.exe application to open it
- ProduKey will launch and immediately display your product keys in the current OS including MS Office keys
- To get to your old Windows Keys, click on File > Select Source
- On the new popup window, choose ‘Load the product keys from external windows directory’
- Click ‘browse’ and Navigate to drive C:\Windows.old (navigate only to the main windows folder)
- If you want to go directly to invoke your registry hive file click on File > Select Source
- Select ‘Load the product keys from external Software Registry hive’
- Navigate to C:/Windows.old/Sytem32/Config/Software where software is the name of your file and not a directory. You can also key in this path if you cannot see it.
- Click OK. Your old Windows Keys Will load
Method 2: Use Magical Jelly Bean Keyfinder utility to view your product key
Unlike ProduKey, Keyfinder scans only windows system folder for your hive files and displays your product keys. The system folders must display the correct directory path otherwise your registry hive files won’t be found.
- Download and install Keyfinder from here
- Launch Keyfinder. From the Tools menu, click Load Hive..
- Navigate your offline Windows directory like C:/Windows.old. The directory structure must be intact as KeyFinder doesn’t allow you to select the SOFTWARE registry hive directly.
- Click OK and wait for Keyfinder to scan and find your keys
Method 2: Use ShowKeyPlus utility to view your product key
ShowKeyPlus scans the entire folder in your system drive and display the keys. Your old Windows product key will be displayed without having to look for it or direct the utility to the registry hive files.
- Download the latest version of ShowKeyPlus software from here (It’s a free software and a portable utility)
- Extract the downloaded zip file to get the executable file.
- Once the app launches, it will show you the current product key, installed version and edition of Windows. It will also automatically retrieve the product key from the Windows.old folder and display it as Original key if the Windows.old folder is located in the root of the drive where the currently running Windows is installed.
- If you have moved the Windows.old folder, click on the option titled Retrieve key from backup, and then navigate to the Windows\System32\Config folder location in your Windows.old folder.
- Select the file named Software, and then click open button to view the product key.
If you direct these utilities to your current OS product key registry hive files located in C:/Windows.old/Sytem32/Config/Software, a conflict might occur since these files are being actively used by the system registry, and they might therefore not display anything back.