System Reserved. It’s 100MB in size and it doesn’t have a drive letter. This 100MB partition is where the Windows boot loader resides. This is needed if you’re going to implement Bitlocker. Installation now by default, prepares the installation for Bitlocker.
This has changed from the Windows Vista / Server 2008 configuration where you have to prepare a drive to support Bitlocker. The installation does not install Bitlocker, it just configures the server in the event you want to enable Bitlocker. This is a much better plan than before.
#32553