What is Boot####?
Quick note explaining Boot#### for BIOS/UEFI and embedded firmware readers.
What is Boot####?
Boot#### variables store individual UEFI boot options.
Why it matters
- Explains how UEFI selects and launches a boot target.
- Helps debug boot option, OS loader, and removable-media issues.
- Connects NVRAM variables with the visible boot menu.
Practical example
Example: if a machine always boots Windows even after selecting USB, check BootNext first, then BootOrder and the device path inside the target Boot#### entry.
Quick checklist
- Does the target Boot#### entry exist and remain active?
- Does BootOrder or BootNext point to the expected entry?
- Does the device path point to a valid ESP and .efi file?
Quick takeaway
Boot#### is part of the chain that turns firmware policy into an actual boot target.
Related notes
- What is BootOrder?
- What is BootNext?
- What is EFI_LOAD_OPTION?
- What is BDS?
- What is Removable Media Boot?
Public references
- UEFI Specification 2.11 — Boot Manager
- EDK II — UefiBootManagerLib/BmBoot.c
- EDK II — UefiBootManagerLib.h
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