Watch-ComputerStatus.ps1

function Watch-ComputerStatus {
<#
.SYNOPSIS
    Live auto-refreshing console dashboard showing status of a set of computers.

.DESCRIPTION
    Polls each computer via Invoke-Command every -RefreshSeconds seconds, collecting
    free disk %, uptime in days, and OS ReleaseID. Results are displayed as a
    colour-coded console table — green for OK, red for thresholds exceeded or offline.
    Runs indefinitely until stopped with Ctrl+C.

    Requires WinRM/PSRemoting on the target computers. Machines that fail Invoke-Command
    are shown as OFFLINE in red.

.PARAMETER ComputerName
    One or more hostnames or IPs to monitor.

.PARAMETER LabelMap
    Optional hashtable mapping hostnames to friendly display names.
    e.g. @{ "PC01" = "Room A"; "PC02" = "Boardroom" }

.PARAMETER RefreshSeconds
    How often to refresh the dashboard. Default: 300 (5 minutes).

.PARAMETER MinFreeDiskPct
    Free disk % below this value is shown in red. Default: 10.

.PARAMETER MaxUptimeDays
    Uptime above this many days is shown in red. Default: 5.

.EXAMPLE
    Watch-ComputerStatus -ComputerName "PC01","PC02","PC03"
    Monitor three machines with default thresholds.

.EXAMPLE
    Watch-ComputerStatus -ComputerName "PC01","PC02" -LabelMap @{PC01="Boardroom"; PC02="Huddle Room"} -RefreshSeconds 60
    Monitor with friendly names, refreshing every minute.

.EXAMPLE
    Get-ADComputer -Filter * -SearchBase "OU=Labs,DC=contoso,DC=com" |
        Select-Object -ExpandProperty Name |
        Watch-ComputerStatus -MaxUptimeDays 7
    Pull computer list from AD and monitor with a 7-day uptime alert.

.NOTES
    Stop with Ctrl+C.
    OS column shows the Windows ReleaseID registry value (e.g. 22H2, 23H2).
    Requires WinRM enabled on targets.
#>
    param(
        [Parameter(Mandatory, ValueFromPipeline)]
        [string[]]$ComputerName,

        [hashtable]$LabelMap     = @{},
        [int]$RefreshSeconds     = 300,
        [int]$MinFreeDiskPct     = 10,
        [int]$MaxUptimeDays      = 5
    )

    begin { $allComputers = [System.Collections.Generic.List[string]]::new() }
    process { $allComputers.AddRange($ComputerName) }

    end {
        $colorCol = {
            param($val, $bad)
            $e     = [char]27
            $color = if ($bad) { "91" } else { "92" }
            "$e[${color}m$val${e}[0m"
        }

        $columns = @(
            @{ Label = "Label";    Expression = { & $colorCol ($_.Label.PadRight(16))    ($_.Online -eq "OFFLINE") } }
            @{ Label = "Hostname"; Expression = { & $colorCol ($_.Hostname.PadRight(16)) ($_.Online -eq "OFFLINE") } }
            @{ Label = "Online";   Expression = { & $colorCol ($_.Online.PadRight(10))   ($_.Online -eq "OFFLINE") } }
            @{ Label = "FreeDisk"; Expression = { & $colorCol ("$($_.FreeDisk)%".PadRight(10))       ($null -ne $_.FreeDisk -and $_.FreeDisk -lt $MinFreeDiskPct) } }
            @{ Label = "Uptime";   Expression = { & $colorCol ("$($_.Uptime) days".PadRight(12))     ($null -ne $_.Uptime   -and $_.Uptime   -gt $MaxUptimeDays) } }
            @{ Label = "OS";       Expression = { $_.OS } }
        )

        Write-Host "Starting dashboard — press Ctrl+C to stop."

        while ($true) {
            $results = Invoke-Command -ComputerName $allComputers -ErrorAction SilentlyContinue -ErrorVariable NoReach -ScriptBlock {
                [pscustomobject]@{
                    Hostname = $env:COMPUTERNAME
                    Online   = "OK"
                    FreeDisk = [math]::Round(
                        (Get-CimInstance Win32_LogicalDisk -Filter "DeviceID='C:'" |
                         ForEach-Object { $_.FreeSpace / $_.Size * 100 }), 1)
                    Uptime   = ((Get-Date) - (Get-CimInstance Win32_OperatingSystem).LastBootUpTime).Days
                    OS       = (Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion' -Name ReleaseID -ErrorAction SilentlyContinue).ReleaseID
                    Label    = $null
                }
            }

            $offline = $NoReach.CategoryInfo.TargetName | ForEach-Object {
                [pscustomobject]@{ Hostname = $_; Online = "OFFLINE"; FreeDisk = $null; Uptime = $null; OS = $null; Label = $null }
            }

            $results = @($results) + @($offline)
            foreach ($r in $results) {
                $r.Label = if ($LabelMap.ContainsKey($r.Hostname)) { $LabelMap[$r.Hostname] } else { $r.Hostname }
            }

            Clear-Host
            Write-Host "Updated: $(Get-Date)   [refresh every ${RefreshSeconds}s — Ctrl+C to stop]"
            $results | Sort-Object Label | Format-Table -Property $columns -HideTableHeaders |
                Out-String | ForEach-Object { $_.Trim() } | Write-Host

            Start-Sleep -Seconds $RefreshSeconds
        }
    }
}