#Requires -Version 5.1
<#
    JbTecWiz Support Centre -- generated fix script

    Fault : "Bootmgr is missing" / 0xc000000f / 0xc0000225 -- the boot configuration is broken
    Fix   : Rebuild the EFI boot files
    Source: https://jbtecwiz.com/support/win-boot-repair

    Run as     : Windows Recovery Environment
    Expect     : 30 minutes
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    A UEFI machine. Nothing here touches the Windows partition's contents.

    HOW TO UNDO IT
    bcdboot can simply be run again -- it is idempotent. Export the store
    first with bcdedit /export if you want a copy.

    This script walks the fix one step at a time and asks before each
    one. Steps with no command are things you do yourself -- it prints
    those and waits. Run with -DryRun to print without executing.

    --------------------------------------------------------------------
    NO WARRANTY - USE AT YOUR OWN RISK

    This script is provided by JbTecWiz as-is and with no warranty of any
    kind, express or implied. You run it entirely at your own risk.

    JbTecWiz accepts no liability for any loss or damage arising from its
    use, including but not limited to data loss, downtime, or configuration
    changes that turn out to be wrong for your system.

    You are responsible for reading this script before running it, for
    satisfying yourself that it suits the machine in front of you, and for
    having a working backup first. Some steps cannot be undone.
    --------------------------------------------------------------------
#>

[CmdletBinding()]
param(
    # Print every step and command without running anything.
    [switch]$DryRun,
    # Do not ask before each step. Read the script first if you use this.
    [switch]$Unattended
)

$ErrorActionPreference = 'Stop'
$script:Failed = 0

function Write-Rule { param([string]$Text)
    Write-Host ''
    Write-Host ('-' * 70) -ForegroundColor DarkGray
    if ($Text) { Write-Host $Text -ForegroundColor Cyan }
}

function Show-Prose { param([string]$Text, [string]$Colour = "Gray")
    if (-not $Text) { return }
    $words = $Text -split "\s+"; $line = "  "
    foreach ($w in $words) {
        if (($line.Length + $w.Length) -gt 74) { Write-Host $line -ForegroundColor $Colour; $line = "  " }
        $line += "$w "
    }
    if ($line.Trim()) { Write-Host $line -ForegroundColor $Colour }
}

function Invoke-Step {
    param(
        [int]$Number, [string]$Do, [string]$Why,
        [scriptblock]$Command, [switch]$Manual, [string]$Shell = "powershell"
    )
    Write-Rule "  Step $Number of 6"
    Show-Prose $Do "White"
    if ($Why) { Write-Host ""; Show-Prose $Why "DarkGray" }

    if ($Manual) {
        Write-Host ''
        Write-Host '  -> Do this yourself, then press Enter to carry on.' -ForegroundColor Yellow
        if (-not $Unattended -and -not $DryRun) { [void](Read-Host) }
        return
    }

    Write-Host ''
    foreach ($l in ($Command.ToString().Trim() -split "`n")) {
        Write-Host ("    " + $l.Trim()) -ForegroundColor Green
    }
    Write-Host ''

    if ($DryRun) { Write-Host "  (dry run -- not executed)" -ForegroundColor DarkGray; return }
    if (-not $Unattended) {
        $a = Read-Host "  Run this step? [Y]es / [S]kip / [Q]uit"
        if ($a -match "^[Qq]") { Write-Host "  Stopped at your request."; exit 0 }
        if ($a -match "^[Ss]") { Write-Host "  Skipped." -ForegroundColor DarkGray; return }
    }
    try { & $Command }
    catch {
        $script:Failed++
        Write-Host ("  Step $Number failed: " + $_.Exception.Message) -ForegroundColor Red
        Show-Prose "The rest of the fix may depend on this. Read the write-up before carrying on." "Red"
        if (-not $Unattended) {
            $c = Read-Host "  Carry on anyway? [y/N]"
            if ($c -notmatch "^[Yy]") { exit 1 }
        }
    }
}

Write-Rule
Write-Host '  "Bootmgr is missing" / 0xc000000f / 0xc0000225 -- the boot configuration is broken' -ForegroundColor White
Write-Host '  Rebuild the EFI boot files' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   30 minutes'
Write-Host ''
Show-Prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.' 'DarkYellow'
Write-Rule

if (-not $Unattended -and -not $DryRun) {
    $go = Read-Host '  Ready? [y/N]'
    if ($go -notmatch "^[Yy]") { Write-Host "  Nothing was changed."; exit 0 }
}

Invoke-Step -Number 1 -Do 'Boot installation media, choose Repair your computer -> Troubleshoot -> Command Prompt.' -Manual

Invoke-Step -Number 2 -Do 'Find the Windows volume and the EFI System Partition. The ESP is the small FAT32 one, usually 100-500 MB.' -Command {
    cmd.exe /c 'diskpart & list volume'
}

Invoke-Step -Number 3 -Do 'Give the ESP a drive letter so bcdboot can write to it.' -Command {
    cmd.exe /c 'select volume 2 & assign letter=S & exit'
}

Invoke-Step -Number 4 -Do 'Rewrite the boot files. This is the single command that fixes most of these.' -Why 'D: is the Windows volume as WinRE sees it, S: the ESP. Getting these the wrong way round writes a boot store that points at nothing.' -Command {
    cmd.exe /c 'bcdboot D:\Windows /s S: /f UEFI'
}

Invoke-Step -Number 5 -Do 'If it reports failure, format the ESP and try again -- it is disposable and rebuilt entirely by bcdboot.' -Why 'Only do this once you are certain S: is the ESP and not a data partition. Check with `list volume` again before formatting anything.' -Command {
    cmd.exe /c 'format S: /FS:FAT32 /Q & bcdboot D:\Windows /s S: /f UEFI'
}

Invoke-Step -Number 6 -Do 'Exit and restart. In firmware, make sure Windows Boot Manager is first in the boot order.' -Manual

Write-Rule "  Confirm it worked"
Show-Prose 'Windows starts. Confirm the store looks sane once in.' 'White'
Write-Host ''
if (-not $DryRun) {
    cmd.exe /c 'bcdedit /enum {bootmgr}'
}

Write-Rule
if ($script:Failed -gt 0) {
    Write-Host ("  Finished with " + $script:Failed + " failed step(s).") -ForegroundColor Yellow
    Show-Prose 'Read the full write-up at https://jbtecwiz.com/support/win-boot-repair' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: bcdboot can simply be run again -- it is idempotent. Export the store first with bcdedit /export if you want a copy.' 'DarkGray'
Write-Rule