Script to disable RDP - powershell

Question

I'm trying to disable RDP using powershell.
I've tried the following code, but the values on the machine name I'm listing aren't changing.
$file = Get-Content c:\PSscripts\regchange\computers.txt
foreach ($computername in $file){
$PingStatus = Gwmi Win32_PingStatus -Filter "Address = '$computername'" | Select-Object StatusCode
If ($PingStatus.StatusCode -eq 0){
$reg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $computername )
$regKey= $reg.OpenSubKey("System\\CurrentControlSet\\Control\\Terminal Server" ,$true)
$regKey.SetValue("fDenyTSConnections","1",[Microsoft.Win32.RegistryValueKind]::dword)
}
else {
Write-Host "$computername unreachable"
}
}
I suspect there's something wrong with the way I entered the registry path name. any help would be appreciated.

Answer 1

The issue must be either permissions (which I assume you have as there are no obvious error messages), refreshing issue or in Get-Content and the structure of your file.
In order for Get-Content to work in this manner, each computer on a separate line. e.g.:
MyComputer1
MyComputer2
Another troubleshooting step is to try adding in Write-Host $computername entries to verify that you are looping through properly.:
$file = Get-Content c:\PSscripts\regchange\computers.txt
foreach ($computername in $file){
$PingStatus = Gwmi Win32_PingStatus -Filter "Address = '$computername'" | Select-Object StatusCode
If ($PingStatus.StatusCode -eq 0){
Write-Host "$computername set"
}
else {
Write-Host "$computername unreachable"
}
}
You can also confirm by adding in a $regKey.GetValue after setting:
$file = Get-Content c:\PSscripts\regchange\computers.txt
foreach ($computername in $file){
$PingStatus = Gwmi Win32_PingStatus -Filter "Address = '$computername'" | Select-Object StatusCode
If ($PingStatus.StatusCode -eq 0){
$reg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine', $computername )
$regKey= $reg.OpenSubKey("System\\CurrentControlSet\\Control\\Terminal Server" ,$true)
$regKey.SetValue("fDenyTSConnections","1",[Microsoft.Win32.RegistryValueKind]::dword)
Write-Host "$computername set to: $($regKey.GetValue("fDenyTSConnections"))"
}
else {
Write-Host "$computername unreachable"
}
}
Manually setting $computername = "MyComputer" and running the code, I can confirm that the code for setting the registry works... I can also confirm that remotely killing your RDP access to your remote virtual workstation also works.. and... is as terrible as it sounds ;-)

Answer 2

If PSRemoting is enabled, try something like this …
(This needs to be executed in a PowerShell elevated admin session.)
Get-Content -Path 'c:\PSscripts\regchange\computers.txt' |
ForEach{
If (Test-Connection -$PSItem -Count 1 -Quiet)
{
$paramblock = #{
Path = 'HKLM:\System\CurrentControlSet\Control\Terminal Server'
Name = 'fDenyTSConnections'
Value = '1'
}
Invoke-Command –Computername $PSItem –ScriptBlock {Set-ItemProperty #paramblock}
}
Else
{Write-Warning -Message "Either the host $PSItem is offline or not reachable."}
}