Recover Windows XP Product Key from ntuser.dat in Corrupted or Unbootable System
Product key, or used to more commonly known as CD key or serial number for Windows XP is as good as the license to use the operating system. Although you may have the paper license for the OS, however due to introduction of Windows Genuine Advantage (WGA) anti piracy feature (see ways to bypass), if Windows XP is installed with invalid or wrong product key, the users will be subjected to much annoyance. Thus if you don’t record down the product key, the product key may be lost once you reformat or reinstall Windows, or the computer corrupts and unbootable.
There are plenty of ways and tools that can be used to retrieve product key from Windows XP, as long as you can still manage to boot and log on to Windows. If Windows corrupted, hard disk corrupted, system no longer functional or computer no longer able to boot up, the tricks will not be able to work. In the case where you need to recover a lost product key from an inaccessible Windows environment, utility by Dagon Design may be useful.
Instructions
The first step is getting the ntuser.dat file from the computer. In most cases the easiest method is to remove the hard drive, and connect it to a working machine.
ntuser.dat is generally located here:
C:\Documents and Settings\(User Name)\ntuser.dat
Where (User Name) is the primary account – Most often it is ‘Owner’ or ‘User’Now that you have the file, you need to be able to view it. I recommend loadhive.exe (Download it here) from matcode.com.
Just run the program and select the file. It will show you a message with more information. It is important that you do not close this program until you are finished viewing the registry, as it temporarily loads the file, and unloads it again when you exit.
Now 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.
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.
0000 00 00 00 00 00 00 00 00 ..
0008 00 00 00 00 00 00 00 00 ..
0010 00 00 00 00 00 00 00 00 ..
0018 00 00 00 00 00 00 00 00 ..
0020 00 00 00 00 00 00 00 00 ..
0028 00 00 00 00 00 00 00 00 ..
0030 00 00 00 00 11 11 11 11 ..
0038 11 11 11 11 11 11 11 11 ..
0040 11 11 11 00 00 00 00 00 ..
0048 00 00 00 00 00 00 00 00 ..
0050 00 00 00 00 00 00 00 00 ..Now that you have the 15 byte encrypted code, you can type it into my decrypter tool:
Web-based version
Downloadable stand-alone version (exe)
Just click ‘Decrypt Code‘ and you will have your 25 digit Windows XP product key!
Troubleshooting
If you cannot find the DigitalProductId key in the file you loaded earlier, try the software hive located here:
\%SystemRoot%\System32\config\software
Load it the same way as before. Under regedit, it will generally create the new entries here: HKEY_LOCAL_MACHINE\SOFTWARE_00 (although the loadhive program will tell you where it puts it).
Related posts:
- Easily Change Product Key with Windows Product Key Update Tool Free Download
- Windows Key Checker to Log and Record Vista and XP Product CD Serial Key
- How to Change Windows Vista Product Key
- Users Self-Leak Windows Vista Home Premium and Ultimate OEM Product Key
- Download Windows Vista RC1 Direct from Microsoft and Product Key Crack





Thanks!! Saved me quite alot of trouble, though i had to get the digitalproductid through the software dat file in system 32.
After finding out I have to open Hive with admin rights for it to load, I can't find anything in the registry grrrr, I am not paying Microsoft again for windows just because the bloody sticker is worn under my laptop! They have conned enough out of our pockets over the years, when will windows finally be free so we don't need to worry about this every year or so!
Hello,
very nice tutorial, but the decrypter did not give the right product key..
[...] know if it's been answered yet but found this stuff Recover Windows XP Product Key from ntuser.dat in Corrupted or Unbootable System My Digital Life provides a link to a download to read the .dat file but the NTUSER dat file is actually one of [...]
Tried both methods – ntuser.dat and the config folder – hives loaded ok in both cases – but no key found. Could find the key and decrypt it for my working machine ok. I guess I've had it unless anyone can come up with another bright idea.
Despite this – a brilliant post – will definitely add it to my arsenal of 'useful stuff'.
I'm curious. Loading a hive is easy. It's like one or two API calls. Finding the key programmatically is also fairly easy. The hard part was decrypting the original key – which is the part you've done.
Why not add the first two steps right into your app so the user doesn't have to use three apps and have to remember all these details?
Just a thought.
This is one kickass time saver. My hat is off to you and I am indebted to you. I've been looking for such a tool for a long time. Great job.
Just wanted to say thanks Jinx – that was a life saver I really thought I was lost till I was your post.
And thanks for the original article!!
Nahh this isnt how you do it for all systems,its close tho. I couldnt locate my key thru the ntuser.dat(XP HOME), I had to use a different file. the software file inside the windowssystem32config folder.
So for me I cannot boot my drive, so I stick it in a second computer (working) and can read the drive (aka non damaged disk, just unbootable)
first go get the loadhive program and run it, go to the unbootable drive and find the software file in the config dir. Not the .sav or .LOG files, the one without the extension. Load it as stated by the guy above and follow the rest of his instructions.
this is good stuff, for years iv been trying to format pcs but cudnt coz they didnt have their keys.
the hard part is getting into documnts and settings (sumtimes ucant cos it protected)
and a downside is u have to open the pc to take out the HDD, but hey its worth it!