Finding lost Windows CD Key

Windows CD Key is the 29 letter key which you have enter during or after the Windows setup process. If you lose your Windows CD key in Windows XP, Vista or 7, do not worry as the key is right there inside the Windows Registry. With the proper tool you can find it out. Here is how :

1. Finding your own Windows CD Key

  1. Download to your Windows Desktop.
  2. Extract the contents of the downloaded zip file to a folder.
  3. Double-click on the WinCDKey.exe file. It will immediately show you your Windows CD Key.

2. Finding other non-bootable computer’s CD key

Suppose you want to find the Windows CD key of Windows installed on a computer which does not boot (for some reason). You can find it out in the following manner. So far this method has been tested for only dead Windows XP based computers. Before you proceed, download to your Windows Desktop and extract the contents of the downloaded zip file to a folder.

  1. What we need is the access to the Windows Registry files of the non-bootable computer. You can take out the hard disk of the non-bootable computer and attach it to a working computer as a secondary drive. There are other ways to access them, like boot from a bootable linux CD and copy the Registry files to a USB drive etc. The Registry files are located in %windir%System32Config. We need only the System file located there.
  2. In the working computer start Windows Registry Editor. You can do this by pressing key combination Windows logo key + R to open the Run dialog, typing regedit in the Run dialog and pressing Enter.
  3. In the Registry Editor, select the HKEY_LOCAL_MACHINE branch by clicking on it.
  4. From the menu, select File → Load Hive. Browse to the System file that we discussed in the Step 1 and click Open.

  5. Registry Editor will ask you for a key name. Type any name you like. Try to use a small name with no spaces. I typed Trisha as shown. Click OK to proceed.

  6. Because we typed the key name to be Trisha, the hive will be loaded under HKEY_LOCAL_MACHINETrisha as shown

  7. Expand the loaded hive. You would find a subkey named WPA. Under this subkey, you would find another subkey starting with key- and terminating in many random letters as shown. Select this subkey by clicking on it. You would be able to see a value DigitalProductID under it.

  8. From the menu, select Edit → Copy key name.
  9. Create a new text file in the same folder in which you extracted wincdkey.exe. Type the following in the text file:
    wincdkey “TrishaWPAKey-XXXXXXXXX”

    Note that you have to replace “TrishaWPAKey-XXXXXXXX” with whatever you find in the Step 7. Do not forget to surround the key in double quotes. Do not type the HKEY_LOCAL_MACHINE part. Notice there is a space after wincdkey.

  10. Save the file. Rename the file as run.cmd. Double-click on this file and the Windows CD key of the non-bootable computer would be shown.
  11. After this is done, in the Registry Editor, select the loaded hive key (in our case Trisha) by clicking on it. Then from the menu, select File → Unload hive. Choose Yes in the confirmation dialog.