"The data collection and transfer in question are part of some of our update download services, such as the Windows Update service. As with other programs downloaded via these services, the success or failure of WGA Notifications' installation is sent to Microsoft," Microsoft UK anti-piracy manager Michala Alexander said in a statement.
He added: "If the user interrupts installation of WGA Notifications, we send the number of the screen on which installation stopped (first, second, etc.). In order to establish an accurate count, we also generate several globally unique identifiers (GUIDs) that do not contain any personal information. We use the GUIDs to tally the number of individual machines without identifying the user. Other data sent includes user and machine language settings and whether or not the machine was joined to a domain."
Source:
The Register