Software & Apps Backup & Utilities How to Find Product Keys and Serial Numbers Using Keyfinder By Tim Fisher General Manager, VP, Lifewire.com Tim Fisher has 30+ years' professional technology support experience. He writes troubleshooting content and is the General Manager of Lifewire. our editorial process Facebook Twitter LinkedIn Tim Fisher Updated December 22, 2018 Backup & Utilities Design Cryptocurrency MS Office Windows Linux Google Drive Apps File Types Backup & Utilities View More Tweet Share Email Keyfinder Thing is a free program that will find your Windows product key and the product keys and serial numbers to many other programs as well. Keyfinder Thing v3.1.6 works for nearly any Windows operating systems except Windows 10, Windows 8, and Windows NT. You need the original product key that came with your Windows purchase before you can reinstall Windows. For a quick overview of what Keyfinder Thing can do, plus some things we don't like about it, see our complete review of Keyfinder Thing v3.1.6. 01 of 07 Visit the Keyfinder Thing Website Keyfinder Thing Website. Keyfinder Thing is a free software program that finds product keys and serial numbers, so the first thing you need to do is visit the Keyfinder Thing website so you can download the program. Keyfinder Thing is a completely free program and you should not be charged anything to download or use it. The detailed instructions I've put together here walk you through the entire process of using Keyfinder Thing to locate lost product keys and serial numbers so feel free to take a look at the entire tutorial before you get started. 02 of 07 Click on the Download Button Keyfinder Thing Download Page. On the Keyfinder Thing download page, above the Keyfinder Thing screenshot, you should see two buttons that say Download. Click the Download button on the left - the one on the right is for a different program that isn't free. 03 of 07 Download the Keyfinder Thing ZIP File Keyfinder Thing Download Process. After clicking the Download button, Keyfinder Thing should begin downloading . The download is in the form of a ZIP file named keyfinderthing3.zip. If prompted, choose to Save to Disk or Download File - your browser may phrase it differently. Save the file to your Desktop or some other location that's easy to locate. Do not choose to Open the File or Open. The Keyfinder Thing ZIP file is very small. Even on slow connections, the download shouldn't take more than a few seconds. The screenshot above shows the download process for Keyfinder Thing when downloading using the Internet Explorer browser in Windows Vista. If you're downloading on another operating system like Windows XP or using a browser other than IE, your download progress indicator will probably look different than the one above. 04 of 07 Extract the Program From the Keyfinder Thing ZIP File Extract Files Dialog Box (Windows Vista). Open the Keyfinder Thing ZIP file after the download is complete. ZIP files are single files that contain compressed versions of one or more files. To be able to use the file(s) contained in the ZIP file, it must be uncompressed. There are several programs that do this and you may have one installed. Because of this, you may have to follow slightly different steps to "unzip" the Keyfinder Thing ZIP file. If you don't have a file extraction program installed, a built-in ZIP extraction feature in Windows will prompt you to extract the files contained within the ZIP file to a new folder. Follow the instructions given to complete the file extraction. 05 of 07 Run the Keyfinder Thing Program Extracted Files View (Windows Vista). After extracting the Keyfinder Thing ZIP file to a folder, open the folder to view the contents. You should see just one file called KeyFinderThing.exe. You may not see the EXE file extension, so just make sure you see the file. If you don't, download and extract the Keyfinder Thing ZIP file again. Double-click on the KeyFinderThing.exe file to run Keyfinder Thing. Keyfinder Thing does not actually install on your PC - it simply runs. If you have trouble locating the file, it's the one with the hammer and wrench icon as shown in the screenshot above. The picture above shows what the folder with the extracted Keyfinder Thing application file looks like in Windows Vista. If you're using a different Windows operating system, your folder may not look the same. 06 of 07 View Your Product Keys and Serial Numbers Keyfinder Thing v3.1.6. After a short scan, Keyfinder Thing displays the product keys and serial numbers to the programs that it's aware of. Your Windows operating system product key will be one of the keys displayed. The PC that I used as an example was a Windows Vista computer but it did not have any additional programs installed. Your computer will likely show several other serial numbers. 07 of 07 Document Your Found Product Keys and Serial Numbers Once you've found your product keys and serial numbers, print them out and keep them somewhere safe! There's no need to go through this process twice. Did you have trouble using Keyfinder Thing or did it not find the serial number you were looking for? Try another free product key finder program. Keyfinder Thing is great but if it doesn't work as you expected, it's not of much use. Another free key finder program might find what you're looking for.