When right clicking on these protected partitions, the menu is greyed out and disable, or simply cut-shorted with most options not available. The partition cannot be merged into any other existing partition either.

As most of these disk partitions is protected and locked by the operating systems to prevent and avoid accidental deletion of these partitions, they cannot be deleted by using Disk Management snap-in. These special partitions, which can be hidden from view, or without any drive letter assigned, can have a size of from few gigabytes to 10 GB or more. comes with special OEM, EISA or EFI partition either in FAT or NTFS file system that contains boot loaders, system recovery utility to rollback to original default factory settings, diagnostic tools, device driver files, system utility programs and system configuration files that are used by the firmware at boot time or to be run before an operating system is booted, and/or for other purposes. Most if not all OEM desktop computers or notebook PCs from Dell, HP, Lenovo, Acer, ASUS, Samsung, Alienware, Sony, Fujitsu, Toshiba and etc. However, Disk Management is limited in its ability, especially when dealing with hidden, system, reserved, recovery and system partitions that are protected by Windows operating system. Disk Management can be accessed via Control Panel -> System and Security -> Administrative Tools -> Computer Management -> Disk Management under Storage tree, or directly via diskmgmt.msc command.

Disk Management of Windows operating system is a simple yet effective tool to initiate, create, delete, manage and format disk partitions or volumes.

Can i delete oem partition