Retrieve Server Uptime

Uses the WMI to pull system uptime with WMI timeouts, it will useful when remote WMI not responding.

I have used it for a few hundred servers and it works fine. The initial test-connection uses only 1 ping, so that it can go through a large list of servers very easily.

If you found any bug then report to [email protected]

# Writer = Ritesh Parab; fb.com\parab.ritesh   
# File Name = Get-uptime 1.2 
# WMI Query time function added {Thanks to Technet forum} 

cls                                              
$erroractionpreference = "SilentlyContinue" 
# Helper Function - convert WMI date to TimeDate object 
function WMIDateStringToDate($Bootup) { 
 [System.Management.ManagementDateTimeconverter]::ToDateTime($Bootup) 
} 

# Main script 
$Computer = Get-Content "c:\Servers.txt" 

foreach ($system in $Computer) { 
$rtn = Test-Connection -ComputerName $system -Count 1 -BufferSize 16 -Quiet 
         IF($rtn -match 'True') { 
        $NameSpace = "Root\CIMV2" 
        $wmi = [WMISearcher]"" 
         $wmi.options.timeout = '0:0:15' #set timeout to 10 seconds 
         $query = 'Select * from Win32_OperatingSystem' 
         $wmi.scope.path = "\\$system\$NameSpace" 
         $wmi.query = $query 
          Try{ 
          $wmiresult = $wmi.Get() 
          #    $wmiresult 
            foreach ($wmioutput in $wmiresult){ 
               $Bootup = $wmioutput.LastBootUpTime 
               $LastBootUpTime = WMIDateStringToDate($Bootup) 
               $now = Get-Date 
               $Uptime = $now - $lastBootUpTime 
               $d = $Uptime.Days 
               $h = $Uptime.Hours 
               $m = $uptime.Minutes 
               $ms= $uptime.Milliseconds 
               $a = "$System Up for: {0} days, {1} hours, {2}.{3} minutes" -f $d,$h,$m,$ms 
               Write-Host "$a" -ForegroundColor Green 
                 } 
              } 
        Catch { 
                  Write-host "WMI not available on : $System" -ForegroundColor Red 
                Write-Output "WMI failed on $system because : $_" | Out-File "d:\failed.txt" -Force -Append  
          } 
        } 
        else{ 
            write-host "$system Offline" -ForegroundColor DarkRed 
            Write-Output "$system Offline" | Out-File 'd:\wintech\Get-Uptime\failed.txt' -Force -Append  
        } 
    }

http://gallery.technet.microsoft.com/scriptcenter/Get-Server-Uptime-Using-WMI-15aaa8ac