Windows Product Activation (WPA)Windows Product Activation (WPA)
on Windows XP
Version 3.2 — Last Updated Novemnber 15, 2005

by Alex Nichol, MS-MVP
© 2001-2005 by Author, All Rights Reserved


One new feature in Windows XP that has caused great concern is Windows Product 
Activation (WPA). There are a great many rumors, and much misinformation, from 
which you might be led to think that WPA is going to call Microsoft every day 
and say just what you are doing with your computer; that, if you make any 
changes at all to your computer hardware, the machine will be instantly 
disabled; and that WPA is a sneaky way for Microsoft to store personal 
information about you or your computer, or to begin charging you a monthly fee 
for your continued use of Windows XP. In fact, all of these rumors are false. 
WPA is a fairly easy-going check when Windows boots, confirming that it is still 
installed on the same computer as last time it checked. That’s all. But the 
rampant misinformation is understandable, because it is hard for the general 
consumer to find a simple yet comprehensive explanation of just what WPA is. 
This page tries to fill that gap by explaining WPA in a straightforward, 
detailed way — and to show that it will be a lot less trouble to most people 
than many have feared.


What’s the idea of WPA?
The Microsoft License for use of Windows has always been limited to allowing 
installation on only a single machine (and that excludes having the same copy 
installed on a laptop as well as a desktop machine: only MS Office is licensed 
for the combination). Microsoft believes that this has been subject to much 
casual abuse. WPA is a means of ensuring that a single copy is not installed on 
more than a single machine.
So, within the first 30 days after installing Windows XP, you must get the 
system ‘activated’ if you are to be able to go on using it. This involves the 
computer dialing in and giving some information about the hardware on which 
Windows is installed, receiving in return a release code which will be recorded 
on the system. More is said below about OEM copies provided preinstalled on a 
new computer
At subsequent boots, Windows checks to see that it is still running on hardware 
that it can recognise as being the same. If it does not match well enough, you 
will be unable to do more than backup files until you call Microsoft to explain 
— for example, that the old machine broke down and had to be rebuilt — and get a 
new release code.


What hardware gets checked?
The WPA system checks ten categories of hardware:
  Display Adapter 
  SCSI Adapter 
  IDE Adapter (effectively the motherboard) 
  Network Adapter (NIC) and its MAC Address 
  RAM Amount Range (i.e., 0-64mb, 64-128mb, etc.) 
  Processor Type 
  Processor Serial Number 
  Hard Drive Device 
  Hard Drive Volume Serial Number (VSN) 
  CD-ROM / CD-RW / DVD-ROM 
It then calculates and records a number based on the first device of each type 
that was found during setup, and stores this number on your hard drive. 
Initially, this is sent to Microsoft in an automatic dial-up, together with the 
Product ID number derived from the 25-character unique Product Key used in 
setting up Windows.
If Service Pack 1 has been installed, the entire Product Key is also 
transmitted: This can then be checked against a list of known pirated keys
The hardware is checked each time Windows boots, to ensure that it is still on 
the same machine. Also, if you subsequently perform a complete format and 
reinstall of Windows, Microsoft’s activation center will have to be contacted 
again because the information held on the machine itself (the number previously 
written to your hard drive) will have been wiped out by reformatting the hard 
drive. If your hardware is substantially the same, this will be done by an 
automated call without your needing to talk to anyone.
What does ‘substantially the same’ mean? WPA asks for ‘votes’ from each of these 
ten categories: ‘Is the same device still around, or has there never been one?’ 
Seven Yes votes means all is well — and a NIC, present originally and not 
changed, counts for three yes votes! Minor cards, like sound cards, don’t come 
into the mix at all. If you keep the motherboard, with the same amount of RAM 
and processor, and an always present cheap NIC (available for $10 or less), you 
can change everything else as much as you like.
If you change the device in any category, you have lost that Yes vote — but will 
not lose it any more thereafter if you make changes in that category again. So, 
for example, you can install a new video display card every month for as long as 
you like.
Note that it appears that if you boot with a device disabled (disabled — not 
removed), the device is not found in the enumeration — so if, say, you disable a 
network connection which uses the NIC and then reboot, you may be missing its 
three votes and find that a new activation is needed. If you are doing such 
things, take the Hint 3 in What about formatting a hard disk? below, and restore 
the files concerned once the NIC is back in service.


What if I make too many changes?
If, on Windows startup, there are not the required seven Yes votes, the system 
will, in the original version of Windows XP, only boot to Safe Mode. You will be 
required to reactivate by a phone call to Microsoft. You will have to write down 
a 50-digit number, call into the activation center on a toll-free number that 
will be given to you, read and check back the number you recorded — and explain 
the circumstances. In exchange, you will be given a 42-digit number to type in. 
This will reactivate your copy of Windows.
This is made easier if Windows XP Service Pack 1 has been installed: The system 
will continue to boot normally for three days, during which time you will be 
able to contact the activation center via the net. If the extra changes have 
been removed, or if 120 days have passed since the original activation, you will 
be able to use the automatic process once more 


What about formatting a hard disk?
Two things are recorded for disks: the number of the disk drive itself, and the 
Volume Serial Number (VSN) of the partition on it.
HINT No. 1: The VSN is part of the data in the partition’s first sector, so it 
is changed when you reformat the drive. It is worth getting the freeware utility 
Volume ID to restore the original VSN. Before you reformat, run VOL from a 
Command Prompt, note the VSN (e.g., 1F2E-3C4B) in the second line. Then, after 
the reformat and new Windows XP installation, defer the new activation until you 
have run Volume ID to restore the old VSN, and rebooted. This is not essential — 
but it saves one of the ‘Yes votes’ against any future hardware change. (If you 
don’t wish to run this utility, the next best way to obtain the same result 
would be to delete the old Win XP files from the hard drive before reinstalling, 
rather than actually reformatting.)
HINT No. 2: Another thing that changes the VSN is converting a FAT 32 partition 
to NTFS. So, if you upgrade a system using FAT 32 to Windows XP and intend to 
convert to NTFS, do the conversion before activating the system. Remember, you 
can wait a while: you have 30 days before you need to activate. The machine’s 
hardware at the time of the first activation is what counts. Or, if you have 
already activated, use Volume ID as described in Hint No. 1. If you are doing 
this after activation, also first back up the WPA.DBL and WPA.BAK files, as 
described in Hint No. 3 below, and, after completion of the conversion, restore 
these files and reboot again.
HINT No. 3: It is valuable to back up the two files WPA.DBL and WPA.BAK from the 
Windows\System32 folder.Then, should they get damaged, or should you do a 
‘Repair’ reinstallation of Win XP, these files can be copied back to restore the 
prior activation status. However, this only works in those limited 
circumstances. The contents of these two files is matched to the specific 
Windows setup; therefore, contrary to what many journalists and members of the 
user community have written in recent months, restoring these files will not 
restore your activation status following a reformat and clean install.
The disk drive and partition recorded will be the ones that the system has found 
first when doing the initial activation: normally the one from which the system 
booted. So, if you change that disk and reinstall Windows to a new partition, 
you have lost two of the Yes votes. If, though, you add a new hard disk, copy 
the original partition onto it with an imaging program, and retain the original 
hard drive as a secondary data disk, it will still be found by a later check. 
This is because it searches for all disks, and the vote will be Yes in both 
categories if it finds the original one, with the partition not reformatted.


What about a swappable hard drive bay?
Provided the swappable hard drive bay is for secondary disks (used for data), 
and the boot disk with Windows is still present, the swappable disks do not 
enter into the WPA calculation.


Changing the motherboard
Installing a replacement motherboard will change the IDE controller, and usually 
will mean that you change to a new, faster, processor. If the processor is one 
with a serial number (Pentium III), then you lose a third vote — including when 
you change to a processor with no serial number, such as an Athlon. If you also 
add RAM, or if the motherboard is one with an on-board SCSI adapter, that makes 
four or five categories now voting No — you would need an unchanged NIC to avoid 
having to call in for reactivation. If the new motherboard also has inbuilt 
video (and possibly even a NIC of its own!), you run right out of Yes votes with 
this one hardware change.
Again, this doesn’t stop you from making such a hardware change, nor from using 
Windows XP thereafter. The phone-in reactivation option was created for just 
this type of situation. Also, this is an extreme example. Due to the onboard 
features of some motherboards, this one hardware change is equivalent to several 
changes at once.


Re-activation on a new setup after adding devices
If you add devices, as mentioned earlier in relation to hard disks, the check at 
boot up will still find the original device, even if it is now in a subsidiary 
postion (e.g., as a slave hard disk). But if you format and do a new setup, it 
will be the device that is now in ‘first place’ that goes into the hardware hash 
sent to Microsoft. This means that this hardware category no longer will match — 
and will be seen as voting ‘no.’ This means that you may find the automatic 
activation rejected, even though you have not recently made any changes. 
Therefore, from the point of view of WPA, it is best to make such hardware 
additions subsidiary ones. For example, if you add another CD drive, have it as 
the secondary slave, and, if need be, move the original one onto the primary 
channel.
There is a useful program XPInfo which will give you a simple picture of which 
categories are currently casting Yes votes at the boot-up check.


How long does this go on?
The license for a retail version of Windows XP is in perpetuity. You get to use 
Windows XP forever, if you choose.
But Microsoft recognises that machines do get upgraded. If, following the 
activation after setup, you do not need to contact the activation center for 120 
days (any changes you make during this time being seen as acceptable when the 
system boots), then the sheet is swept clean and you can start again using the 
current hardware as the new baseline to make more changes.
If you get a new computer, you are entitled to remove Windows XP from the one 
that is being junked, and install the same Windows XP on the new machine — but 
you will have to do the reactivation by a voice call and explain (unless, as was 
just mentioned, 120 days have passed since the activation was last performed).
Microsoft has said that if it ever becomes not worthwhile for them to keep this 
activation system going, they will take steps to allow users to disable it.


OEM versions
Restrictions of specific license types may limit the foregoing. OEM versions of 
Windows XP are licensed together with the hardware with which they are 
purchased, as an entity, and such a copy may not be moved to a different 
computer. Also, other specific license types (e.g., Academic licenses) are 
handled in different ways. These aren’t a WPA issue per se, but rather an issue 
of the license for that purchase, and therefore outside the scope of this 
discussion of WPA.
There are two versions of OEM Windows XP systems. One can be purchased 
separately, with qualifying subsidiary hardware, and installed with that 
hardware to an existing machine, to which it becomes bound. The software may be 
reinstalled and reactivated indefinitely as with a retail system as long as it 
is still on the original machine. It may not be transferred to a different 
computer. It is activated as described above, but if it were installed to 
hardware seen as not substantially the same, the activation would be refused as 
falling outside the license.
In the other OEM form, the system is provided pre-installed by a major supplier. 
Instead of activation, the system is ‘locked’ to the BIOS on the motherboard. 
The validity of this lock is checked at boot. As long as this is satisfied, 
other hardware may be changed freely, but any replacement motherboard must be 
for a compatible one supplied by the original maker.
If a BIOS-locked system is installed to a board where the lock fails, it enters 
a normal Activation process at startup. However, beginning 1 March 2005, the 
Product Key supplied on a label by the computer manufacturer, and used for the 
initial intallation, will not be accepted for activation. A new copy of Windows 
XP, with a license allowing installation on a different machine, will be needed. 
This means that any replacement motherboard (or upgrade to its BIOS) must be 
supplied by the original maker, who will ensure the lock is maintained.


Installation of Service Packs 1 & 2
Windows XP Service Pack 1 (“SP1”) introduces some further obstacles to systems 
that appear to have been pirated: It will not install at all on systems which 
appear to have used one of two well established “pirate” Product Keys, and a 
wider range of pirated and cracked keys will result in no access being allowed 
to Windows Update. These limitations are taken further with Service Pack 2
Installation of SP1 also will detect and fix a number of “cracks” used by 
pirates to circumvent the need to activate. Such systems will then need to be 
activated after SP1 is installed. However, regular, legitimate, installations of 
Windows XP will not need to be reactivated after simply because of installing 
SP1.
For more detailed discussion of the changes and their implications, see 
Microsoft’s article Service Pack 1 Changes to Product Activation.


Some things WPA does not do
  WPA does not send any personal information at all about you to Microsoft. 
  There is still an option to register the product with Microsoft, but that is 
  separate and entirely voluntary. 
  If you have to phone in yourself to carry out an activation or reactivation, 
  you are not required to give any identifying personal information. 
  WPA does not ‘phone in’ every day to check. The check that the system is not 
  significantly different is done by Windows itself at boot. If the hardware is 
  not acceptable (i.e., you don’t get your seven Yes votes), you have to 
  initiate the telephone call yourself in order to reactivate. Windows itself 
  never calls Microsoft except when you specifically tell it to do so for an 
  online activation. 
  WPA does not provide a means for Microsoft to turn off your machine or damage 
  your data. (Nor do they even have access to your data.) If the system is 
  requiring you to phone in, you will still be able to boot to Safe Mode and 
  back up your data. 
  WPA is not a “lease” system requiring more payments after two years or any 
  other period. You may use the product as licensed in perpetuity.