Microsoft is bringing its Office anti-piracy download to the UK. The program works by 'nagging' users of Office if it has determined that that copy is illegitimate.

The expansion follows a pilot programme Microsoft launched in Chile, Italy, Spain and Turkey in April 2008, then extended to an additional 24 countries. This is the first time, however, that Microsoft has asked UK users to install a notifications component that pesters users of pirate software.

Microsoft said the download of the notification component was "voluntary", and that it has already started to push the software to users. Because the program is launching over several months, not everyone will see it immediately.

For Windows XP users, the update is marked ‘High Priority' in the list generated when they retrieve downloads from Microsoft Update; Vista users see it tagged as ‘Important'. Even if users have Automatic Updates set to download and install all updates, the notifications software requires users to accept an End User License Agreement (EULA) before it will install.

However, once it's downloaded and installed, the new notifications application cannot be uninstalled.

The notifications component that Microsoft is pitching is separate from the companion validations element: The former posts periodic messages on the screens of PCs running illegal copies of Office, while the latter determines if the software is legitimate.

At one time, Office users had to validate their copies in order to access add-ons, such as free Office 2007 templates, and to use Office Update, an Office-only service that was just terminated in favor of the combination Windows-Office service dubbed 'Microsoft Update'.

Last spring, Microsoft dropped those requirements, and allowed users running counterfeit copies to download add-ons. With the disappearance of Office Update earlier this month, all users can grab security and bug-fix updates via Microsoft Update, regardless of the status of their software.

According to Microsoft's support site, Office Genuine Advantage Notifications software puts up a message when a pirated copy is launched. "This copy of Microsoft Office is not genuine," the message reads.

"Please excuse this interruption. This copy of Microsoft Office did not pass validation. Click Learn More for details and for help identifying the best way to get genuine Microsoft Office."

Microsoft also adds a message-bearing toolbar to Office XP and Office 2003, and adds a similar message to the ‘ribbon' interface of Office 2007. "This copy of Office is not genuine. Click here to learn more," the toolbar and ribbon messages read.

Office 2010, the still-in-the-works version slated to ship in the first half of next year, will also include antipiracy validation and notification elements.

Last year, Microsoft inadvertently pushed the pilot notifications programme to customers worldwide via Windows Server Update Services (WSUS). This triggered a flood of false warnings, getting system administrators hot under the collar.

To make matters worse, the notifications update to WSUS machines had been ranked 'critical', which meant most corporate update servers automatically approved it and pushed it to client PCs.

"The ultimate goal of our programs that stem the flood of piracy is not only to lessen the impact of these illegal activities, but also to ensure that our customers enjoy all the capabilities - as well as the peace of mind - that come with using genuine software," said Cori Hartje, senior director of Microsoft's anticounterfeit group.

"Non-genuine software has been shown to be more vulnerable to viruses and spyware, which can be used to damage a user's PC or steal their personal information," added a Microsoft spokeswoman.

Users whose copies of Office 2007 are flagged as bogus - and only Office 2007; earlier editions aren't eligible - may qualify for a free replacement through Microsoft's Office Complimentary Offer.