"As it stands today, Microsoft’s policy allows pirated copies to receive patches automatically through AutoUpdate, yet forbids them from downloading them directly from Microsoft’s Web site. Despite some tweaks to its policy, however, the company continues to make it difficult for users of pirated versions of its operating system to patch reliably.
A significant issue is when Microsoft periodically slips Windows Genuine Advantage (WGA) into the stream of security updates. This type of subversive act has a very negative effect, likely convincing many users to forego updating rather than find their machine crippled. " – Content courtesy of Microsoft’s Stance on Piracy Affects Us All