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

    Fault : 0x80070035 -- "the network path was not found" reaching a share
    Fix   : Deal with the refusal of insecure guest logons properly
    Source: https://jbtecwiz.com/support/win-net-smb-access

    Run as     : Elevated PowerShell on the client
    Expect     : 20 minutes
    Risk       : high
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    A NAS or appliance share that used to open without a password. Read the
    warning in the first step before doing this.

    HOW TO UNDO IT
    Set AllowInsecureGuestAuth back to 0 and restart LanmanWorkstation. Do
    this as soon as the device is replaced.

    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 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 '  0x80070035 -- "the network path was not found" reaching a share' -ForegroundColor White
Write-Host '  Deal with the refusal of insecure guest logons properly' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: high   Reversible   20 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 'Understand what is being traded. Guest SMB access is unauthenticated and unsigned -- anyone on the network can read what it exposes and a man in the middle can alter it in flight. The correct fix is to create a real user on the NAS and connect with credentials; the switch below is for equipment that genuinely cannot do that.' -Manual

Invoke-Step -Number 2 -Do 'First try the right way -- a named account on the device.' -Command {
    cmd.exe /c 'net use Z: \\nas\share /user:nasuser * /persistent:yes'
}

Invoke-Step -Number 3 -Do 'Only if the device cannot authenticate at all, re-enable guest logons.' -Why 'This is the setting behind "You can''t access this shared folder because your organization''s security policies block unauthenticated guest access". It is a client-wide switch, not per-share.' -Command {
    Set-ItemProperty -Path 'HKLM:\SYSTEM\CurrentControlSet\Services\LanmanWorkstation\Parameters' -Name AllowInsecureGuestAuth -Type DWord -Value 1
}

Invoke-Step -Number 4 -Do 'Restart the workstation service.' -Command {
    Restart-Service LanmanWorkstation -Force
}

Write-Rule "  Confirm it worked"
Show-Prose 'The share opens, and Get-SmbConnection shows the dialect in use so you know what you are actually running.' 'White'
Write-Host ''
if (-not $DryRun) {
    Get-SmbConnection | Format-Table ServerName,ShareName,Dialect,Encrypted
}

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-net-smb-access' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Set AllowInsecureGuestAuth back to 0 and restart LanmanWorkstation. Do this as soon as the device is replaced.' 'DarkGray'
Write-Rule