Windows Product Key Recovery

Sometimes we face a problem whereby we need to format a PC but found out that the product key of that PC is missing or can’t be read. So, how to get it back? There are many programs available for extracting the product key from a Windows XP or Vista installation. The only problem is that they generally require the computer to be functional to run. Here, I will show you how you can retrieve the product key with just the ntuser.dat file from the machine.

1. Get the ntuser.dat file from the computer. Location:

Windows XP – C:\Documents and Settings\(Username)\ntuser.dat
Windows Vista – C:\Users\(Username)\ntuser.dat
*** Where (Username) is the primary account name.

2. Now, you need to be able to view the ntuser.dat file. Try using loadhive.exe. Just run the program and select the ntuser.dat file that you’ve just got.

3. Run regedit. Under HKEY_LOCAL_MACHINE you will notice a new sub-key called NTUSER. Starting with NTUSER go to Software > Microsoft > Windows NT > Current Version. In the right window, double-click on DigitalProductID. This is the entry that contains the encoded product key.

4. We want the information in bytes 52 to 66. You can use the chart below for reference. We need the 15 sets of numbers where the 1’s are located.

5. Now that you have the 15 byte encrypted code, you need a decrypter tool to decode those:

XP Key Decrypt
Win Key Finder

6. Walla! You should get your 25 digit Windows product key! Good Luck

Source: DagonDesign