Windows 8 tells Microsoft about everything you install
Known computer security researcher Nadim Kobeissi has posted up some interesting information on the behavior of Windows 8 whenever you install an application. According to some quick researching he did, the Windows SmartScreen feature reports every application a user installs to Microsoft, and does so in a way that could be intercepted by malicious hackers.
The Windows SmartScreen feature is enabled by default and is designed to tell end users whether the application they have downloaded from the internet is safe to install on their machine. It does this by gathering some info upon opening the installer, sending it to Microsoft and then waiting for a response to see if said installer has a valid certificate. As Kobeissi mentions, this means information about every single application downloaded and installed is sent to Microsoft.