How to change a product key on Windows XP

Microsoft kb328874

Note We recommend that you run System Restore to create a new restore point before you follow these steps.

Deactivate Windows

  1. Click Start, and then click Run.
  2. In the Open box, type regedit, and then click OK.
  3. In the navigation pane, locate and then click the following registry key:
    HKEY_LOCAL_MACHINE\Software\Microsoft\WindowsNT\Current Version\WPAEvents
  4. In the topic pane, right-click OOBETimer, and then click Modify.
  5. Change at least one digit of this value to deactivate Windows.
Reactivate Windows and add new product key

  1. Click Start, and then click Run.
  2. In the Open box, type the following command, and then click OK.
    %systemroot%\system32\oobe\msoobe.exe /a
  3. Click Yes, I want to telephone a customer service representative to activate Windows, and then click Next.
  4. Click Change Product key.
  5. Type the new product key in the New key boxes, and then click Update.

    If you are returned to the previous window, click Remind me later, and then restart the computer.

  6. Repeat steps 1 and 2 to verify that Windows is activated. You receive the following message:
    Windows is already activated. Click OK to exit.
  7. Click OK.

Switch Off Active Desktop in WinXP

  1. From the Windows Start menu, select Run. In the Run box, type regedit and click OK.
  2. In the Registry Editor, locate the following key:
  3. Create a new DWORD Value with the name ClassicShell, and assign a value of 1 to it.
  4. Close the Registry Editor.
  5. Reboot

Can’t start Registry in WinXP

Sometimes you can not run Regedit. This is due to a setting in the registry itself.

When you try to run Regedit, you get a message like “Registry editing has been disabled by your administrator” or something similar.

To resolve this run the following command:

REG add HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System /v DisableRegistryTools /t REG_DWORD /d 0 /f

This should get you the instant result.

How to edit remote registry

When you are loaded up from WinXP boot CD, you can edit registry on existing installation on the HDD.

  1. Start Regedit.
  2. Go to HKEY_USERS
  3. Select File -> Load Hive.  Point to C:\Windows\System32\Config. Inside this folder select one of the files i.e software, SAM, system etc.
  4. Type new name for the folder to mount the remote registry… like REMOTE_System or REMOTE_Software.
  5. Now remote registry is loaded into regedit and you can change things there just like in normal registry.
  6. After done changes, you MUST unload the hives: File -> Unload Hive.

Check HKEY_USERS\Remote_Software\Microsoft\Windows NT\CurrentVersion\Winlogon

Shell entry must be pointing to Explorer.exe.

Userint should point to C:\Windows\System32\Userinit.exe

Win XP is not executing any applications or *.exe files

When WinXP is not executing any applications or *.exe files, this likely that the system is full of viruses, so better do a full scan with anti-virus that is run from bootable CD (there are a lot of them available, like Hiren’s CD or bootable Dr.Web).

After virus clean-up download this registry fix file and run it. This should fix the problem.

Vista wireless problem

Problem: Vista can not connect to wireless network.. the system can not see the DHCP server in router and getting 169.254.x.x ip address which is private and no use at all.
To resolve this go to registry, find
Where GUID is a id for that network adapter – you will see the difference if another one is wired and connected.
Add new entry (DWORD 32), call it DhcpConnDisableBcastFlagToggle and assign value 1.
Change entry DhcpConnForceBroadcastFlag to 0.
Try to reconnect.