PowerShell Get Windows OS Version Fast and Do Different Things - arrays

Question

Is there a faster way to get a specific registry value from a list of servers? I'm selecting a text file of computers with different flavors of windows and getting the OS product name. I'm finding that it's taking a couple seconds per computer to retrieve.
Current script:
Clear-Host
# Prompt for file containing list of target
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
$myDialog = New-Object System.Windows.Forms.OpenFileDialog
$myDialog.Title = "Select File of Target Systems"
$myDialog.InitialDirectory = $PSScriptRoot
$myDialog.Filter = "TXT (*.txt) | *.txt"
$result = $myDialog.ShowDialog()
If ($result -eq "OK") {
$Computers = Get-Content $myDialog.FileName
}
Else {
Write-Host "`nCancelled by User`n"
}
$Array = #()
# Loop Through Computers
ForEach ($Computer in $Computers) {
Write-Warning "Processing $Computer"
# Get Registry Values
Try {
$OSVersion = Invoke-Command -ComputerName $Computer -ScriptBlock { (Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion" -Name ProductName).ProductName }
# Create a custom object
$ComplexObject = New-Object PSCustomObject
$ComplexObject | Add-Member -MemberType NoteProperty -Name "Server name" -Value $Computer
$ComplexObject | Add-Member -MemberType NoteProperty -Name "OS Version" -Value $OSVersion
# Add custom object to our array
$Array += $ComplexObject
}
Catch {
$_.Exception.Message
Break
}
}
# Results
If ($Array) {
# Display results in new window
$Array | Out-GridView -Title "OS Version Results"
# Display results in PS console
$Array
}
My end goal later on in the script is to do different things based on the OS version so I want to separate them into independent lists:
If (We have Win2008 servers) {
"Do This"
}
If (We have Win2012R2 servers) {
"Do This"
}

Answer 1

Clear-Host
# Prompt for file containing list of target
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
$myDialog = [System.Windows.Forms.OpenFileDialog]::new()
$myDialog.Title = "Select File of Target Systems"
$myDialog.InitialDirectory = $PSScriptRoot
$myDialog.Filter = "TXT (*.txt) | *.txt"
$result = $myDialog.ShowDialog()
If ($result -eq "OK") {
$Computers = Get-Content $myDialog.FileName
}
Else {
Write-Host "`nCancelled by User`n"
}
# Get Registry Values
$Array = Try {
Invoke-Command -ComputerName $Computers -ScriptBlock {
(Get-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion" -Name ProductName).ProductName
} -ErrorAction stop | Select-Object #{n="Server Name";e={$_.pscomputername}},
#{n="OS Version";e={$_}}
}
Catch {
write-warning $_.Exception.Message
break
}
# Results
If ($Array) {
# Display results in new window
$Array | Out-GridView -Title "OS Version Results"
# Display results in PS console
$Array
}

Answer 2

You can use Get-AdComputer like:
Get-ADComputer -Filter {(OperatingSystem -like "*windows*server*") -and (Enabled -eq "True")} -Properties OperatingSystem | Select -ExpandProperty OperatingSystem | ForEach {
If($_ -match "Windows Server 2008.*"){
# Server 2008
}
If($_ -match "Windows Server 2012.*"){
# Server 2012
}
# Add more like 2016,2019
}