PCs now have UEFI firmware rather than the BIOS they once had. Hard disk drives in systems with UEFI firmware may have an "EFI System Partition", which will be fairly small, e.g. about 100 MB, which may be a third partition on drives that may have an operating system, such as Microsoft Windows on one partition and system recovey software on another partition. The EFI partition must be formatted with the FAT12, FAT16, or FAT32 file system. The partiton will store boot loader code for operating systems, such as Windows, installed on other partitions and may also store device drivers needed by the firmware.
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