update

function Get-Info {
    [cmdletbinding()]
    param([parameter(
    Mandatory=$True,
    ValueFromPipeline=$true,
    ValueFromPipelineByPropertyName=$true
    )]
    [alias('hostname')]
    [string[]]$ComputerName
    )

    BEGIN{
         $everything = @()
    }

    PROCESS{

        foreach ($Computer in $ComputerName) {
            #only scan WMI if the computer responds to ping
            Write-Verbose "Pinging $computer"
            if(test-connection -ComputerName $computer -Count 1 -Quiet){
            Write-Verbose "$Computer responded to ping"
                try
                {
                    $CS = Get-WmiObject -Class Win32_ComputerSystem    -ComputerName $Computer -ErrorAction Stop
                    $BS = Get-WmiObject -Class Win32_Bios              -ComputerName $Computer -ErrorAction Stop
                    $OS = Get-WmiObject -Class Win32_OperatingSystem   -ComputerName $Computer -ErrorAction Stop
                }
                catch
                {

                   "$(get-date) - $computer failed the wmi call!" | out-file c:\errorlog.txt -Append
                   $error[0].Exception.Message | out-file c:\errorlog.txt -Append
                }

                Write-Verbose "Switchy switches!"
                switch ($CS.AdminPasswordStatus)
                {
                    '0'     {$AdminPasswordStatus = "Not set" }
                    '1'     {$AdminPasswordStatus = "Disabled"}
                    '2'     {$AdminPasswordStatus = "Enabled"}
                    '3'     {$AdminPasswordStatus = "N/A"}
                    '4'     {$AdminPasswordStatus = "Unknown"}
                    Default {$AdminPasswordStatus = "FAIL!"}
                }

                switch -Wildcard ($OS.Version)
                {
                    '6.1.7600'   {$OS.Version = "7"}
                    '6.1.7601'   {$OS.Version = "7 SP1"}
                    '*9200*'     {$OS.Version = "8/2012"}
                    '*9600*'     {$OS.Version = "8.1/2012R2"}
                    Default      {$OS.Version = "OLD!"}
                }


                #create new object for current computer
                $thiscomputerobj  = [pscustomobject][ordered]@{
                    ComputerName  = $Computer.toupper();
                    Domain        = $CS.Domain;
                    AdminPW       = $AdminPasswordStatus;
                    Model         = $CS.Model;
                    Manufacturer  = $CS.Manufacturer;
                    SerialNumber  = $BS.SerialNumber;
                    Version       = $OS.Version;
                    #ServicePack  = $OS.ServicePackMajorVersion
                }

                #add the current computer to the summary object
                $everything += $thiscomputerobj


            }#end test-connection if

        }#end foreach

    }#end Process


   End{
        Write-Verbose 'End'
        $everything
   }

}#end function

Get-Info