Microsoft has strengthened its policy to fight against piracy. The WGA, Windows Genuine Advantage is a fine example of their determination. However, installing the WGA is considered by Microsoft as a security update since June 2006.
For those having a legal Windows license, it is no problem. For others, the trouble begins as a form of message pop-up, that reminds them of how often they use a counterfeit version of Windows. In addition, the illegal users will not be able to perform system updates.
In addition, WGA communicates with a Microsoft server at each system restart. Of course, Microsoft says WGA "does not collect or send any information that could be used to identify or contact a user" (quote Microsoft).
"Remove WGA" automates the uninstall of this feature, at the risk of the user.