DB-hub Technology 未分类 Create Windows Boot Manager

Create Windows Boot Manager

2025-12-302025-12-30| sophonsophon| 0 Comment| 19:29
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Clone using Macrium Reflect (UEFI-safe)
Step 1 — Install

Download & install Macrium Reflect Free

Run it as Administrator

Step 2 — Select source disk

Choose the disk that currently boots Windows (Disk 0)

Click “Clone this disk…”

Step 3 — Select destination disk

Choose your target disk (SSD / Disk 1)

If it has partitions → Delete Existing Partitions

Step 4 — Copy all partitions

Make sure ALL are copied:

✅ EFI System Partition (FAT32, ~100–300 MB)

✅ MSR (16 MB)

✅ Windows (C:)

✅ Recovery partition

You can resize the Windows partition to use full disk space.

Step 5 — Start clone

Click Next → Finish

Wait until complete

Do not interrupt

Step 6 — Boot from cloned disk

Reboot → ESC → F9 (HP Boot Menu)

Choose Windows Boot Manager (SSD)

If it boots → success 🎉

What NVRAM means
NVRAM is a core concept in UEFI/BIOS booting, and it explains exactly why your 2nd Windows disk doesn’t show up.

In a PC:

  • It’s a small amount of memory on the motherboard
  • It keeps its data even when the laptop is powered off
  • It is NOT on your disks

UEFI firmware uses NVRAM to store:

  • Boot entries (what you see as Windows Boot Manager)
  • Boot order
  • Secure Boot variables

Why NVRAM matters for booting

UEFI does NOT scan all disks every time.

Instead, it boots using pointers stored in NVRAM that say:

“Boot this exact EFI file on this exact disk + partition”

Example of a real NVRAM entry:

Windows Boot Manager
→ Disk GUID: XXXXX
→ Partition GUID: YYYYY
→ \EFI\Microsoft\Boot\bootmgfw.efi

How NVRAM gets populated

NVRAM entries are created by:

  • Windows installer
  • bcdboot
  • Linux installers (grub-install)

They are NOT created automatically just because EFI files exist.

Step 1 — Suspend BitLocker (if active)

Open Command Prompt as Administrator:

manage-bde -protectors -disable D:

This prevents BitLocker from asking for a recovery key when you modify boot entries.

Step 2 — Assign a drive letter to the EFI partition on D:

Open Command Prompt (Admin):

diskpart
list disk
select disk 1       # X = disk number for D: (SSD)
list vol
select vol 1        # Y = EFI partition (~300 MB, FAT32, type: System)
assign letter=S
exit

S: is temporary to access the EFI partition

Look for a volume that is:

  • FAT32
  • ~100–300 MB
  • Type: System

If it doesn’t exist, create one:

select disk 1
create partition efi size=300
format quick fs=fat32 label=EFI
assign letter=S
exit

Step 3 — Use bcdboot to create a Boot Manager

Assuming Windows is installed on C: on Disk 1:

bcdboot C:\Windows /s S: /f UEFI

Explanation:

C:\Windows → path to Windows installation on that disk

/s S: → target EFI partition (the one we just assigned)

/f UEFI → create UEFI boot files

This writes a new Windows Boot Manager entry into NVRAM

Optional: Force a new entry (avoids conflicts with Disk 0)

bcdboot C:\Windows /s S: /f UEFI /c

/c = create a new, unique boot entry even if another exists on another disk

Step 4 — Verify the Boot Manager

bcdedit /enum firmware

You should see two Windows Boot Manager entries:

One pointing to Disk 0 EFI
One pointing to Disk 1 EFI

Disk 1 must be GPT — UEFI boot does not work on MBR for Windows 10/11

Do not use legacy boot mode on HP laptops; firmware may hide the entry

This procedure works for both cloned Windows installs and fresh installs

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