When installing a newer version of Windows on a clean disk with no existing partitions, a System Reserved partition is automatically created at the beginning of the disk. The main purpose of this partition is to reserve space for BitLocker Drive Encryption files. Should you ever decide to encrypt your system with BitLocker after setting it up, you won’t have to repartition in order to make it possible.
One of my work responsibilities is to create and capture SCCM OS images. SCCM captures operating systems as WIM files. WIMs have the ability to hold multiple partitions, and the SCCM capture procedures will grab all partitions including the above mentioned System Reserved if it exists.
You can view how many partitions an existing SCCM OS image contains. Once you’ve captured and imported a WIM into SCCM as an operating system image, access its Properties -> Images (tab). If you see more than one image option available (1-1, 2-2, 3-3, etc.) then you know multiple partitions have been captured. Images (partitions) that don’t have an OS version and architecture listed like the 1-1 pictured below are captured partitions that do not contain Windows. You can click through each image to identify which does include Windows.
Unintentionally capturing multiple partitions isn’t necessarily a bad thing…
…because you can simply specify which (partition) image option to apply within a task sequence’s apply operating system step; just make sure it’s the one that actually contains Windows. But I’ve found in my environment that having multiple image options has caused confusion, so it’s proven best to ensure I capture Windows on a single partition so those applying my images in their task sequences don’t accidentally select the wrong image option.
To ensure Windows installs on a single partition, you need to use a partitioning tool to create a single partition before initiating the Windows install. There are many tools that are able to do this, but we’ll use the Diskpart utility since it can be accessed during Windows setup.
First boot into Windows Setup from your installation media. Before you select where you want to install Windows, press Shift + F10 to bring up a command prompt. Assuming you have a clean disk, enter the following commands:
- list disk (verify which disk # is your hard drive)
- select disk 0 (or whichever # is your hard drive)
- create partition primary
Close command prompt and continue with Windows Setup using this new partition as your install location. Once finished, you can see in Disk Management that Windows has installed to a single partition: