When having trouble clearing OEM partitions.
“Failed to reset disk – Cannot clear with OEM partitions present. To clear OEM partitions, use the RemoveOEM flag.”
Launch command prompt and type “diskpart”
Type “list disk” to display all disks
Type “select disk #”
Type “list partition” to display all the volumes on the hard drive.
Type “select partition #”.
Type “delete partition override” to get rid of the volume.
Type “exit” to close