How to find the Windows XP 25-digit product key in the registry?

Click "Start" and click on the program labeled "Run." Type "regedit" into the search box and press the "Enter" key. This will open the registry editor.

Expand the keys labeled "HKEY_LOCAL_MACHINE," "Software," "Microsoft," "Windows NT" and "Current Version," one after the other. Look for a folder labeled "DigitalProductID" and double-click on it. This will show you an encoded version of the product key. You will need to decode it.

Locate the 15 sets of numbers containing the number 1. Follow the link in the bottom.(Decrypt) Enter the 15 sets of numbers into the decrypt box on the Web page, and click on "Decrypt Code." This will show you your 25-digit Windows XP product key.

Tool to Decrypt

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