Evidence obtained by German hardware site tecChannel suggests a list of software installed on an XP machine is sent to Microsoft when users run Windows Update.
When patches are downloaded, a few kilobytes of data are sent in the opposite direction over a secure SSL channel.
Because the data is encrypted a simple packet sniffer can't be used to see what this data contains.
However tecChannel's tecDUMP utility takes advantage of an undocumented WinInet API, enabling an examination of the data before it becomes encrypted.
According to tecChannel, the information sent to Microsoft includes details of all the software installed in a machine, not only Microsoft applications.
The latest version of Windows Update Privacy Statement (which dates from last October) states: "Windows Update must collect a certain amount of configuration information from your computer".
This configuration information includes OS version number, IE version number and "version numbers of other software for which Windows Update provides updates" along with plug and play ID numbers and regional settings.
But there's no mention of collecting data on software from other vendors running on a machine. And this software can't be updated using Windows Update. So why is Microsoft collecting this data?
One for the conspiracy theorists ... ®