When disk management Delete Volume Greyed out, you can try the methods we introduced to delete a partition, not only OEM partition, but also any other partitions, by the way, Delete All Partitions in the option listed in Partition Expert.
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If you are looking for software with friendly graphic-interface instead of command lines, Partition Expert is the best choice to delete the OEM partition, here are the steps: The third step is to determine how large to make the drive partition (called volumes in. Delete the OEM partition in Partition Expert OEM OS cannot go to another computer An OEM (original equipment. If you are not sure which one is the OEM partition, you can check it in Disk management, or in our software Partition Expert. The EFI system partition is a small partition formatted with FAT32, usually 100MB, which stores. (It uses the oem partition only when a specific file is found. Why does the hard disk have EFI and OEM partitions. The system partition doesn't depend on the oem partition. Having different oem partition contents doesn't mean the product software is different. Built per small variations, such as branding and color. Note: Deleted partition will become unallocated space Partition Attributes oem: Not updateable usually flashed once at the factory. This is the fastest way to delete OEM partition in diskpart there's another way to do the same job, FYI, still in diskpart: