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

    Fault : Office is stuck on an old build, or a bad update needs rolling back
    Fix   : Change the update channel
    Source: https://jbtecwiz.com/support/win-office-update-channel

    Run as     : PowerShell as administrator
    Expect     : 1 hour
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    The machine is on the wrong channel -- usually Current when it should be
    Monthly Enterprise, so that updates arrive predictably rather than
    continuously.

    HOW TO UNDO IT
    Set UpdateChannel back to the previous URL and run the update again.

    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.
#>

[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

# This fix is documented as needing an elevated session.
$id = [Security.Principal.WindowsIdentity]::GetCurrent()
if (-not (New-Object Security.Principal.WindowsPrincipal $id).IsInRole(
        [Security.Principal.WindowsBuiltInRole]::Administrator)) {
    Write-Host ''
    Write-Host '  This fix needs an elevated PowerShell.' -ForegroundColor Yellow
    Write-Host '  Close this window, right-click PowerShell, Run as administrator,'
    Write-Host '  and run the script again.'
    Write-Host ''
    exit 3
}

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 4"
    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 '  Office is stuck on an old build, or a bad update needs rolling back' -ForegroundColor White
Write-Host '  Change the update channel' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   1 hour'
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 'Read the current channel.' -Why 'The value is a CDN URL ending in a GUID rather than a name. 492350f6 is Current, 55336b82 is Monthly Enterprise, 7ffbc6bf is Semi-Annual Enterprise, and 64256afe is Semi-Annual Preview.' -Command {
    Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\ClickToRun\Configuration' | Select-Object UpdateChannel, ClientVersionToReport
}

Invoke-Step -Number 2 -Do 'Set the channel. This example moves the machine to Monthly Enterprise.' -Command {
    Set-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\ClickToRun\Configuration' -Name UpdateChannel -Value 'http://officecdn.microsoft.com/pr/55336b82-a18d-4dd6-b5f6-9e5095c314a6'
}

Invoke-Step -Number 3 -Do 'Trigger an update so the change takes effect. Moving to a slower channel can mean a downgrade, which takes a full package download.' -Command {
    & "$env:CommonProgramFiles\Microsoft Shared\ClickToRun\OfficeC2RClient.exe" /update user displaylevel=true forceappshutdown=true
}

Invoke-Step -Number 4 -Do 'For more than a handful of machines, set the channel through the Office administrative templates or Intune instead. Setting it per machine by hand does not survive a rebuild.' -Manual

Write-Rule "  Confirm it worked"
Show-Prose 'The channel value is the one you set and the version settles on a build belonging to that channel.' 'White'

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-office-update-channel' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Set UpdateChannel back to the previous URL and run the update again.' 'DarkGray'
Write-Rule