The Windows computer may come preinstalled with Microsoft Windows operating system and Microsoft Office productivity suite, and the user may not even see or access to the product key, also known as CD key or serial number that is needed to manually install Windows OS and Office System, and to make sure that the products are genuine.

You may simply want to write down and safekeep the Windows and/or Office product CD key or serial number for future usage or for documentation purpose, as the key is as good as license to use Windows and Office. Or you want to get back the CD key that has been forgotten before reinstalling Windows or Office. There are a few tools and utilities that allows you to easily and quickly retrieve the Windows product key and Office CD key or serial number. Some of them has the ability to change the serial key too, in case you need to modify the product key in Windows due to case like 326904 error “The Product Key Used to Install Windows Is Invalid” or incorrect product license key.

Magical Jelly Bean Keyfinder

Magical Jelly Bean Keyfinder is a freeware and free download that let users view and retrieve the product key or CD key used to install Windows, Microsoft Office and many other software from the registry. Magical Jelly Bean Keyfinder currently able to support and reveal product CD key from Windows 95, Windows 98, Windows ME, Windows NT 4.0, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10, Windows Server 2008 (R2), Windows Server 2012 (R2) and so on. For Office, it supports retrieval of product key or CD key or serial number for Office 97, Office XP, Office 2003, Office 2007, Office 2010, Office 2013, Office 2016 and more.

Best of all, Magical Jelly Bean Keyfinder also supports changing the Windows product key without reinstall Windows to another product key or CD key or COA (feature removed since version 2.0). It also can scan another or non-bootable Windows for serials.

Magical Jelly Bean Keyfinder can be downloaded here or directly download the current version: KeyFinderInstaller.exe (download link removed as marked as malware).


ProduKey can recover and display product keys, serial numbers, key code and other license information of more than 1000 software products.

Keyfinder Thing Lite! and KeyFinder Thing 3

Keyfinder Thing Lite! and KeyFinder Thing 3 are utility to find serial numbers or product key licenses from more than 150 application software.

CD Key Reader

CD Key Reader is a small utility that can be downloaded and run immediately without installation. CD Key Reader can only retrieve product CD keys for modern Microsoft applications such as Windows or Office.

Windows Genuine Advantage Diagnostics Tool

Official tool from Microsoft means for WGA (Windows Genuine Advantage) program. However, it can only show the last 15 digits of the Windows CD key. The tool can be downloaded here.

Windows Product Key Update Tool

Another utility from Microsoft that allows Windows users to change or update the product key of Windows OS. However, if you steal or crack somebody else’s CD key or product key, this tool is not recommended, as the Product Key Update Tool will scan a number of key Windows files to determine if they have been tampered with. If tampered files are discovered, the tool will alert you before continuing. And it will also sending the information back to Microsoft about the file tampering scan and Windows validation information. Windows Product Key Update Tool can be downloaded here with more information and usage instructions.


RockXP is a free multi purpose utility that allows users to get all Microsoft software serial number, retrieve you Internet connection parameters such as passwords, retrieve MSN login and password, recover XP login and HASH password, display system password (LSA) and generate random password. RockXP also has the ability to change the product key or serial for Windows XP, and automatically hack and crack to bypass the Windows XP Product Activation.

To view and change the Windows XP serial or CD key, simply click on “Windows key” tab, and click on Scan to retrieve the installed product key, and key in the new CD key serial to change the product key.

RockXP can be downloaded here.


WinGuggle is a small application that have multiple features and functions, including ability to set, change and backup your Original Equipment Manufacturer (OEM) logo and information, recover and retrieve Windows 7/8/10/Vista/XP and Office product key, change performance information and tools OEM logo, remove OEM logo and support information and more. No Installation is needed to run the app.

Download WinGuggle v2.5:

Key Checker

Key Checker is a small yet unique tool to find Windows product key from registry periodically according to the timing set, and log the key found to the screen or file.

AC2T KeyViewer

KeyViewer from AC2T is a free tool that will decode the encoded Windows CD key and Office product key or serial in Windows 98 SE (including other Windows 9x), Windows ME Windows W2K and Windows XP that is stored under “DigitalProductId” registry key under “HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion” registry branch. It also supports users to input raw key retrieved from the registry themselves for the tool to decode to readable product key.

The raw key decoding feature is useful is you unable to login or logon to the Windows, but you need to retrieve the Windows product key or serial for reinstallation or other purpose. By using a bootable CD with a registry editor such as Offline NT Password & Registry Editor CD Bootdisk used primarily for recover or reset password, users can then retrieve the raw key found in ProductId or DigitalProductId registry key by booting up on the CD, and input into KeyViewer for decoding into a valid product key serial.

Download AC2T KeyViewer.

Windows Product Key Viewer/ Changer (Demoware)

Windows Product Key Viewer/Changer (now becomes trialware Recover Keys) can recover lost product keys on an installed and activated Windows XP including Service Pack 2, Windows 98, Windows ME, Windows NT, Windows 2000 and Windows 2003 operating system. It also supports ability to change CD product keys on Windows 98, Windows XP Home and Windows XP Professional without reinstalling Windows.


Win9xProdKey (no longer available) from Vic Ferri reveals CD keys for Windows 95, Windows 98 and Windows Me.


ViewKeyXP (no longer available), also from Vic Ferri, reveals and shows Windows XP CD key and serial number.

View Installed Product Key of Windows Using Script

In newer version of Windows after Windows XP (Windows Vista, Windows 7, Windows 8, Windows 8.1, Windows 10 and Windows Server), the product key is saved in registry key in encoded format. It can be easily decoded with script. Save the following VBScript to a text file with the file extension of .vbs. For example, productkey.vbs. You can save file in different extension in Notepad by changing the “Save as type” to “All Files” when saving the document.

Set WshShell = CreateObject("WScript.Shell")
MsgBox ConvertToKey(WshShell.RegRead("HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\DigitalProductId"))

Function ConvertToKey(Key)
Const KeyOffset = 52
i = 28
Cur = 0
x = 14
Cur = Cur * 256
Cur = Key(x + KeyOffset) + Cur
Key(x + KeyOffset) = (Cur \ 24) And 255
Cur = Cur Mod 24
x = x -1
Loop While x >= 0
i = i -1
KeyOutput = Mid(Chars, Cur + 1, 1) & KeyOutput
If (((29 - i) Mod 6) = 0) And (i <> -1) Then
i = i -1
KeyOutput = "-" & KeyOutput
End If
Loop While i >= 0
ConvertToKey = KeyOutput
End Function

Once saved, run (double click or double tap on) it, and the product key of Windows will be shown in a dialog box.

Manually Viewing and Get the Product Key or CD Key in Windows 9x from Registry

Windows product key is stored in plain text in the Registry and in the file system.dat. In Windows 95, Windows 98 or Windows Me.

To view and retrieve the CD key:

  1. Launch registry editor (click on Start -> Run, key in regedit and click OK).
  2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion registry branch.
  3. Locate the ProductKey in the right pane for Windows 98 and Me, or ProductID for Windows 95 where the Windows CD key serial is stored.

You can also automate the process by creating a batch file with the following commands:

For Windows 98 or Windows Me:

 @echo off
start /w regedit /e key.txt HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
type key.txt|find "ProductKey">mykey.txt
del key.txt

For Windows 95:

 @echo off
start /w regedit /e key.txt HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion
type key.txt|find "ProductID">mykey.txt
del key.txt

Recover the Product Key or CD Key in Windows 9x without Go Into Windows

To retrieve the Windows 95 or Windows 98 product key without getting into Windows itself, download the (no longer available) for Vic Ferri, and copy the extracted batch file to a bootable floppy disk. Boot up and computer with the startup floppy disk, and simply run the key.bat (by typing key or key.bat and press Enter) to get the product key. For Windows 95, edit the batch file and replace the word ProductKey with ProductID.

The batch file contains the following commands to retrieve the product serial from system.dat:

@echo off
find "ProductKey" c:\windows\system.dat

If you’re using Windows 95, make sure the lines look like the following:

@echo off
find "ProductID" c:\windows\system.dat

Manual Retrieve Product Key for Windows XP and Windows 2000 from $WINNT$.INF file

$WINNT$.INF located in \Windows\System32 folder is the file that used by Windows installer to perform unattended or automated installs of Windows NT, 2000 or XP. If the file exists, and you have the administrative rights to access the file, the Windows product key can be found and viewed under the section [User Data] (usually at the top), under the name of ProductKey or ProductID.

Serial Change script for XP and XP SP1 or greater

Download save the Serial Change script for XP (XPChangeSerial.vbs) (no longer available) or Serial Change script for XP with sp1 or greater (XPChangeSerialSP1.vbs) (no longer available). Then execute the VBS script from the command line (you have to go to the location or folder that you save the script in order to run the script) with the syntax:

XPChangeSerial.vbs xxxxx-xxxxx-xxxxx-xxxxx-xxxxx


XPChangeSerialSP1.vbs xxxxx-xxxxx-xxxxx-xxxxx-xxxxx

Change Volume Licensing product key for Windows XP SP1 or later with Activation Wizard or ChangeVLKeySP1.vbs & ChangeVLKey2600.vbs WMI script

Microsoft provides a detailed instructions and step by step guides on how to change the Windows XP VLK product key or serial key by using Activation Wizard, or by using WMI script. Visit KB328874.

Belarc Advisor

Belarc Advisor is the personal computer audit tool that details profile of your installed software and hardware, missing Microsoft hotfixes, anti-virus status, CIS (Center for Internet Security) benchmarks, and etc. Information shown include the Windows product key.

AIDA64 Everest

AIDA64 from FinalWire Everest from Lavalys (discontinued) is a automated network audit, system change tracking, network monitoring solution, system diagnostics and benchmarking solution that will display the Windows product key, among others.

XPPID Windows XP Product Key Modifier

A small application that allows users to easily change Windows XP product key number by entering new valid XP product key into the field provided and the just press the ‘Change Key’ button. Then the application will run the patched activation process so that the Windows is fully activated after reboot.

Download XPPID.

Change Product Key in Windows

Beginning from Windows Vista, most Windows versions have built-in capability to allow user to change the product key by simply click on “Change product key” link. For detailed instructions, visit how to change product key in Windows.

Change Product Key by Using SLMgr

Since Windows Vista, Windows OS includes a tool called SLMgr (Software Licensing Manager), which can be used to change the product key (but not viewing the whole product key except the last 5 characters), and reactivate the Windows. The commands are:

slmgr.vbs -ipk <new product key here&gt
slmgr.vbs -ato

For example, changing product key with SLMgr in Windows.