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

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

    Run as     : Windows Recovery Environment
    Expect     : 25 minutes
    Risk       : medium
    Reversible : NO -- read the undo note below before running

    WHEN THIS IS THE RIGHT FIX
    A legacy BIOS/MBR machine.

    HOW TO UNDO IT
    The renamed BCD.old can be put back. The MBR itself cannot be restored
    without an image.

    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 MBR boot records' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   NOT REVERSIBLE   25 minutes' -ForegroundColor Yellow
Write-Host ''
Show-Prose 'Undo: The renamed BCD.old can be put back. The MBR itself cannot be restored without an image.' 'Yellow'
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 to Command Prompt.' -Manual

Invoke-Step -Number 2 -Do 'Rewrite the master boot record and the boot sector.' -Why '/fixmbr overwrites the MBR code. If a third-party boot manager such as GRUB is installed there, this removes it -- reinstall it afterwards from the other OS.' -Command {
    cmd.exe /c 'bootrec /fixmbr & bootrec /fixboot'
}

Invoke-Step -Number 3 -Do 'Scan for Windows installations and add what it finds.' -Command {
    cmd.exe /c 'bootrec /scanos & bootrec /rebuildbcd'
}

Invoke-Step -Number 4 -Do 'If rebuildbcd reports zero installations, rebuild the store by hand.' -Command {
    cmd.exe /c 'ren C:\Boot\BCD BCD.old & bootrec /rebuildbcd'
}

Invoke-Step -Number 5 -Do 'If /fixboot returns Access Denied, the partition is not marked active.' -Command {
    cmd.exe /c 'diskpart & select disk 0 & select partition 1 & active & exit'
}

Invoke-Step -Number 6 -Do 'Restart.' -Manual

Write-Rule "  Confirm it worked"
Show-Prose 'Windows boots and bcdedit lists a valid entry.' 'White'
Write-Host ''
if (-not $DryRun) {
    cmd.exe /c 'bcdedit /enum'
}

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: The renamed BCD.old can be put back. The MBR itself cannot be restored without an image.' 'DarkGray'
Write-Rule