Introduction to Macrium Reflect X
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      1. Macrium Reflect X
      2. Introduction to Macrium Reflect X

      Understanding Windows Partitions

      - What are MBR and GPT?

      - UEFI Systems with GPT-Initialized Disks

      - BIOS Systems with MBR-Initialized Disks

      What are MBR and GPT?

      Master Boot Record (MBR) and GUID Partition Table (GPT) are two different ways of storing partition and boot information on a disk and are closely coupled with the two different types of computer firmware: BIOS and UEFI.

      BIOS, and by extension MBR disks, are now considered legacy and have largely been replaced by UEFI firmware and GPT disks. GPT disks, the newer of the two partitioning schemes, have several advantages over MBR disks. MBR disks are limited to having 4 primary partitions with a maximum disk size of 2.2TB, whereas GPT disks have a maximum number of 128 partitions with a theoretical maximum disk size of 18 EB (Exabytes).

      MBR and GPT initialized disks will contain different partitions, as described below.

      UEFI Systems with GPT-Initialized Disks

      UEFI systems with GPT-initialized disks will generally contain the following partitions:

      Partition Unique Identifier Description
      Windows Recovery de94bba4-06d1-4d40-a16a-bfd50179d6ac There may be more than one recovery partition:
      Windows RE Tools       - Provides the 'Startup Repair' options for Windows recovery.
      Recovery Image - There may also be an additional manufacturer system recovery partition.

      EFI System partition (ESP)

      		 c12a7328-f81f-11d2-ba4b-00a0c93ec93b Always formatted FAT32 and between 200 and 300 MB in size, this partition contains the boot loader that runs when the system starts. The critical files in here are the Boot Configuration Data (BCD) and the EFI microcode.
      Microsoft Reserved Partition (MSR) e3c9e316-0b5c-4db8-817d-f92df00215ae

      Usually 128 MB in size, this unformatted partition is reserved for Microsoft data structures, including the logical disk manager (LDM) for dynamic disks. Every GPT disk initialized by Windows includes this partition.

      Note: This partition is not displayed in Windows Disk Management.
      Operating System (Windows C:) ebd0a0a2-b9e5-4433-87c0-68b6b72699c7 Always formatted using NTFS, this partition contains the full Windows Operating System and is loaded using the BCD in the ESP.

      Surface Pro 3 running Windows 10

      BIOS Systems with MBR-Initialized Disks

      Legacy BIOS systems with MBR-initialized disks will generally contain the following partitions:

      Partition

      Description
      Microsoft Reserved Partition (MSR)

      For MBR disks, Windows 7 and above, this is the 'Active' partition and contains the Boot Configuration Data (BCD). This partition provides the second stage for the MBR boot process after the MBR boot code. 

      Windows XP and Vista do not use this partition.
      Operating System (Windows C:) This partition contains the full Windows Operating System.
      For Windows XP and Vista, this is the 'Active' partition and is the only partition required to boot and start Windows.
      WinRE Tools Partition Windows 10 includes this small partition, usually located immediately after the Windows partition, to provide the 'Startup Repair' options for Windows recovery and to store the WinRE image file. 

      Windows 7 MBR System:

      Windows 10 MBR System: