Since last fall the company has been testing a tool that can check whether a particular version of Windows is legitimate, but until now the checks have been voluntary. Starting Feb. 7, the verification will be mandatory for many downloads for people in three countries: China, Norway and the Czech Republic.By summer Microsoft will make the verification process necessary in all countries, otherwise users will not be able to download updates.
In those countries, people whose copies are found not to be legitimate can get a discount on a genuine copy of Windows, though the price varies from $10 to $150 depending on the country
Though there is a small concession, users who have turned on the Automatic Update Feature will still be able to download updates.
More details at Cnet