Check If a program is installed on multiple computers using Powershell - powershell-4.0

Question

I'm having issue with a script I've written and would love some help.
Please note I'm very new to powershell.
I've written a script that uses a txt file that contains remote computers on a domain, I appears to be working to some degree but in the event of a machine being offline I get errors which then loop the script.
$machines
$pcname
Name = 'Machine'
Expression = { $_.PsComputerName }
}
ForEach ($System in $Machines)
{
#Pings machine's found in text file
if (!(test-Connection -ComputerName $System -BufferSize 16 -Count 1 -ea 0 -Quiet))
{
Write-Output "$System Offline"
}
Else
{
#Providing the machine is reachable
#Checks installed programs for products that contain Kaspersky in the name
gwmi win32_product -Filter {Name like "%Kaspersky%"} -ComputerName $Machines | Select-Object -Property $pcname,Name,Version
}
}
At present this runs and output's like so:
Machine Name Version
UKTEST01 Kaspersky Security Center Network Agent 10.1.249
UKTEST02 Kaspersky Endpoint Security 10 for Windows 10.2.1.23
But in the event of a machine not being reachable the following error is given:
gwmi : The RPC server is unavailable. (Exception from HRESULT: 0x800706BA)
At C:\Scripts\Powershell\Kaspersky Endpoint Security 10\Script\New folder\Kaspersky Checker working v2.ps1:15 char:9
+ gwmi win32_product -Filter {Name like "%Kaspersky%"} -ComputerName $Mach ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : InvalidOperation: (:) [Get-WmiObject], COMException
+ FullyQualifiedErrorId : GetWMICOMException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
And then moves to the next machine in the list, and then repeats from the beginning again.
I'd like for this to simply show as:
UKTEST03 Offline
And stop once the last machine in the txt file is done.
Any help or advise would be greatly appreciated.

Answer 1

This is the perfect time to use a Try/Catch/Finally block. The flow is this : Try the block of code here, if you encounter an error, suppress the message and do what is in the Catch block instead.
I've modified your code a bit, so simply copy this whole code block and drop it in, replacing your Else {scriptblock} in your original code.
Else
{
#Providing the machine is reachable
#Checks installed programs for products that contain Kaspersky in the name
Try {Get-WMIObject -Class win32_product -Filter {Name like "%Kaspersky%"} `
-ComputerName $Machines -ErrorAction STOP |
Select-Object -Property $pcname,Name,Version }
Catch {#If an error, do this instead
Write-Output "$system Offline }
}
}
Your completed answer
I've folded in the change you requested, to keep your script from running on every machine in $machines instead of $system, as you likely intended.
ForEach ($System in $Machines){
#Pings machine's found in text file
if (!(test-Connection -ComputerName $System -BufferSize 16 -Count 1 -ea 0 -Quiet))
{
Write-Output "$System Offline"
}
Else
{
#Providing the machine is reachable
#Checks installed programs for products that contain Kaspersky in the name
Try {Get-WMIObject -Class win32_product -Filter {Name like "%Kaspersky%"} `
-ComputerName $System -ErrorAction STOP |
Select-Object -Property $pcname,Name,Version }
Catch {#If an error, do this instead
Write-Output "$system Offline "}
#EndofElse
}
#EndofForEach
}

Answer 2

You could try this:
$machines=... # your machines' names
foreach ($machine in $machines)
{
trap{"$machine`: not reachable or not running WsMan";continue}
if(test-wsman -ComputerName $machine -ea stop){
gcim -Class CIM_Product -Filter 'Name like "%Kaspersky%"' |
select pscomputername,name,version
}
}
I'm using gcim because gwmi is deprecated.
Correction: the correct name is Kaspersky; I corrected it.