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

    Fault : 0xC1900101 -- feature update rolls back
    Fix   : Remove the blockers and retry from mounted media
    Source: https://jbtecwiz.com/support/win-upgrade-c1900101

    Run as     : Windows
    Expect     : 45-90 minutes
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    SetupDiag named a driver, or the extension code points at the boot
    phase.

    HOW TO UNDO IT
    Windows keeps the previous build for 10 days -- Settings -> System ->
    Recovery -> Go back.

    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 5"
    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 '  0xC1900101 -- feature update rolls back' -ForegroundColor White
Write-Host '  Remove the blockers and retry from mounted media' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   45-90 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 'Uninstall third-party antivirus and endpoint agents completely, using the vendor''s removal tool rather than Add/Remove Programs.' -Why 'Filter drivers are the single most common cause of this family. A partial uninstall leaves the filter driver registered.' -Manual

Invoke-Step -Number 2 -Do 'Unplug everything not needed to boot -- external drives, docks, printers, smartcard readers, USB hubs.' -Manual

Invoke-Step -Number 3 -Do 'Remove any VPN client and its virtual adapter.' -Manual

Invoke-Step -Number 4 -Do 'List non-Microsoft drivers and note anything storage or security related that predates the machine''s last two years.' -Command {
    pnputil /enum-drivers
}

Invoke-Step -Number 5 -Do 'Mount the ISO for the target build and run setup from it, choosing to keep files and apps.' -Why 'Running setup from mounted media skips the Windows Update download path entirely, which removes a whole class of failures from the picture.' -Command {
    Mount-DiskImage -ImagePath C:\iso\windows.iso
}

Write-Rule "  Confirm it worked"
Show-Prose 'The upgrade completes and the build number has changed.' 'White'
Write-Host ''
if (-not $DryRun) {
    Get-ComputerInfo -Property OsName, OsBuildNumber
}

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-upgrade-c1900101' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Windows keeps the previous build for 10 days -- Settings -> System -> Recovery -> Go back.' 'DarkGray'
Write-Rule