Reset your serial number in Windows XP
1. Run regedit and go to:
HKey_Local_Machine\Software\Microsoft\WindowsNT\Current Version\WPAEvents
on the right double click on "OOBEtimer" and change at least one digit of this value to deactivate windows.
2. Choose run from start menu and type in this command:
%systemroot%\system32\oobe\msoobe.exe /a
to get the activation screen and go to the second option which is activate by phone.
3. In the new screen choose the option to change product key, and type in the new product key (Corporate one only).
4. Close that window, reboot your system and enter the command in step 2 for the second time to verify your activation you should see "windows is already activated".
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Product Keys affected by WinXP Service Pack 1
Volume License Product Keys: Changes with Windows XP Service Pack 1
Microsoft® Windows® XP Service Pack 1 (SP1) contains three changes of importance to customers using Volume Licensing Keys (VLKs):
Eligibility for Windows XP Service Pack 1.
Eligibility for access to Windows Update.
Ability to encrypt a VLK for unattended setup of Windows XP.
One important thing is not changing: The existing VLK for Windows XP Professional issued to you by Microsoft will continue to work with Windows XP Professional with SP1.
Eligibility for Product Updates
Software updates are intended for use by legally licensed users of Microsoft products. Microsoft is striving to ensure that licensed users continue to get updates uninterrupted by software pirates. Users of pirated software hurt licensed users by taking bandwidth from download servers and software updates intended for licensed users.
Microsoft has determined through investigations that most pirated installations are made with either of two VLKs. VLKs are used by corporate or other volume license customers to install Windows XP on their computers. These two particular VLKs, however, were never in use by a customer in a production deployment. Product keys are 25-character alphanumeric codes arranged in five groups of five characters each and used during setup to install the product. The product key produces the product ID number that, after setup is completed, is displayed on the General tab in the System Properties dialog box.
Windows XP SP1 ships with a list of the two product IDs that are created by the pirated VLKs. To determine eligibility for the update, Windows XP SP1 compares the Windows XP product ID on the system to this list. The comparison and the list reside locally on the user's computer; no information is sent to Microsoft as part of this process. The Windows XP SP1 installation will fail on computers with the following product IDs:
XXXXX-640-0000356-23XXX
XXXXX-640-2001765-23XXX
If installation fails for this reason, this message will be displayed:
Service Pack 1/2 Setup Error
The product key used to install Windows is invalid. Please contact your system administrator or retailer immediately to obtain a valid product key. You may also contact Microsoft Corporation's Anti-Piracy Team by e-mailing piracy@microsoft.com if you think you have purchased pirated Microsoft software.
Please be assured that any personal information you send to the Microsoft Anti-Piracy team will be kept in strict confidence.
To determine the Windows product ID on your computer:
On the task bar, click the Start button.
Right-click My Computer.
On the context menu, click Properties.
On the General tab, examine the number that is listed under Registered to:
System administrators may find it useful to check the product ID through the Registry Editor.
The registry path is:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\ CurrentVersion\ProductId
Licensed customers are not affected by this anti-piracy change.
1. Run regedit and go to:
HKey_Local_Machine\Software\Microsoft\WindowsNT\Current Version\WPAEvents
on the right double click on "OOBEtimer" and change at least one digit of this value to deactivate windows.
2. Choose run from start menu and type in this command:
%systemroot%\system32\oobe\msoobe.exe /a
to get the activation screen and go to the second option which is activate by phone.
3. In the new screen choose the option to change product key, and type in the new product key (Corporate one only).
4. Close that window, reboot your system and enter the command in step 2 for the second time to verify your activation you should see "windows is already activated".
--------------------------------------------------------------------------------------------------
Product Keys affected by WinXP Service Pack 1
Volume License Product Keys: Changes with Windows XP Service Pack 1
Microsoft® Windows® XP Service Pack 1 (SP1) contains three changes of importance to customers using Volume Licensing Keys (VLKs):
Eligibility for Windows XP Service Pack 1.
Eligibility for access to Windows Update.
Ability to encrypt a VLK for unattended setup of Windows XP.
One important thing is not changing: The existing VLK for Windows XP Professional issued to you by Microsoft will continue to work with Windows XP Professional with SP1.
Eligibility for Product Updates
Software updates are intended for use by legally licensed users of Microsoft products. Microsoft is striving to ensure that licensed users continue to get updates uninterrupted by software pirates. Users of pirated software hurt licensed users by taking bandwidth from download servers and software updates intended for licensed users.
Microsoft has determined through investigations that most pirated installations are made with either of two VLKs. VLKs are used by corporate or other volume license customers to install Windows XP on their computers. These two particular VLKs, however, were never in use by a customer in a production deployment. Product keys are 25-character alphanumeric codes arranged in five groups of five characters each and used during setup to install the product. The product key produces the product ID number that, after setup is completed, is displayed on the General tab in the System Properties dialog box.
Windows XP SP1 ships with a list of the two product IDs that are created by the pirated VLKs. To determine eligibility for the update, Windows XP SP1 compares the Windows XP product ID on the system to this list. The comparison and the list reside locally on the user's computer; no information is sent to Microsoft as part of this process. The Windows XP SP1 installation will fail on computers with the following product IDs:
XXXXX-640-0000356-23XXX
XXXXX-640-2001765-23XXX
If installation fails for this reason, this message will be displayed:
Service Pack 1/2 Setup Error
The product key used to install Windows is invalid. Please contact your system administrator or retailer immediately to obtain a valid product key. You may also contact Microsoft Corporation's Anti-Piracy Team by e-mailing piracy@microsoft.com if you think you have purchased pirated Microsoft software.
Please be assured that any personal information you send to the Microsoft Anti-Piracy team will be kept in strict confidence.
To determine the Windows product ID on your computer:
On the task bar, click the Start button.
Right-click My Computer.
On the context menu, click Properties.
On the General tab, examine the number that is listed under Registered to:
System administrators may find it useful to check the product ID through the Registry Editor.
The registry path is:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\ CurrentVersion\ProductId
Licensed customers are not affected by this anti-piracy change.