Many users have questioned why illegal PIDs are being allowed on a Windows XP SP2 installation when they were blocked in previous betas. This is due to Microsoft's new approach on security in Service Pack 2 to prevent any further Windows XP machines from getting infected with viruses and malicious attacks. Microsoft's Gary Schare answers:

"There have been a number of discussions on this newsgroup regarding whether SP2 will install on non-genuine (aka "pirated") versions of Windows. Here is the official Microsoft position on this topic:

We expect that nearly all Windows XP users, running genuine or pirated Windows, will have access to the security technologies in SP2. The same users that were blocked from installing SP1 - those that have used a small set of legacy pirated product keys - will be blocked from installing SP2. We believe that there are very few systems in use today that use these keys -- in other words, the pirates have moved on to other keys which we are not blocking.

So how do we charaterize our policy?

We want to make sure that the broadest number of people can install SP2. The nature of malicious attacks on computer users is constantly changing and we will continue to evaluate how we deal with security updates for pirated versions of Windows to best protect our genuine Windows customers.

Thanks,

Gary Schare
Microsoft"

Source