Powershell Remote Registry Access to Non-Domain Server - powershell

Question

I have the following script which I use to collect the installed applications on various servers:
$results = #()
$list = Get-Content serverlist.txt
foreach ($computer in $list) {
echo "Processing $($computer)"
if (Test-Connection -Cn $computer -BufferSize 16 -Count 1 -ea 0 -quiet ) {
echo "Getting installed apps from $($computer) ..."
$UninstallKey="SOFTWARE\\Microsoft\\Windows\\CurrentVersion\\Uninstall"
echo "Opening remote registry ..."
$reg=[microsoft.win32.registrykey]::OpenRemoteBaseKey('LocalMachine',$computer)
echo "Getting registry keys ..."
if ($reg) {
$regkey=$reg.OpenSubKey($UninstallKey)
if ($regkey) {
$subkeys=$regkey.GetSubKeyNames()
echo "Building result object ..."
foreach($key in $subkeys){
$thisKey=$UninstallKey+"\\"+$key
$thisSubKey=$reg.OpenSubKey($thisKey)
$obj = New-Object PSObject
$obj | Add-Member -MemberType NoteProperty -Name "ComputerName" -Value $computer
$obj | Add-Member -MemberType NoteProperty -Name "DisplayName" -Value $($thisSubKey.GetValue("DisplayName"))
$obj | Add-Member -MemberType NoteProperty -Name "DisplayVersion" -Value $($thisSubKey.GetValue("DisplayVersion"))
$obj | Add-Member -MemberType NoteProperty -Name "InstallLocation" -Value $($thisSubKey.GetValue("InstallLocation"))
$obj | Add-Member -MemberType NoteProperty -Name "Publisher" -Value $($thisSubKey.GetValue("Publisher"))
$results += $obj
}
}
}
} else {
echo "$($computer) is DOWN!"
$obj = New-Object PSObject
$obj | Add-Member -MemberType NoteProperty -Name "ComputerName" -Value $computer
$obj | Add-Member -MemberType NoteProperty -Name "DisplayName" -Value "Down"
$obj | Add-Member -MemberType NoteProperty -Name "DisplayVersion" -Value "Down"
$obj | Add-Member -MemberType NoteProperty -Name "InstallLocation" -Value "Down"
$obj | Add-Member -MemberType NoteProperty -Name "Publisher" -Value "Down"
$results += $obj
}
}
$results | Where-Object { $_.DisplayName } | select ComputerName, DisplayName, DisplayVersion, InstallLocation, Publisher | Export-Csv D:\Temp\InstalledApps.csv
This works fine on all of the domain member servers. The issue comes when I try to get this to work on two non-domain Windows 2008R2 Standard servers. One server works fine and the other server does not. On the server that does not work, I get the following error:
Exception calling "OpenSubKey" with "1" argument(s): "Requested registry access is not allowed."
I cannot figure out why this would work for one server and not the other. I am running the script from a non-elevated Powershell on a Windows 7 x64 machine.
UPDATE:
I used Process Monitor to track what the Remote Registry service was doing on both machines. On the machine where things work OK, I see 4 reads of HKLM\System\CurrentControlSet\Control\SecurePipeServers\winreg and then it starts pulling the information I want from HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall. On the machine where things are not working, Remote Registry does the same 4 reads of the winreg key but then it starts reading HKLM\System\CurrentControlSet\Control\SecurePipeServers\winreg\AllowedPaths and HKLM\System\CurrentControlSet\Control\SecurePipeServers\winreg\AllowedExactPaths. I did some investigation and Remote Registry checks the permissions on the winreg key before proceeding. I compared the good machine and bad machine and the registry keys and permissions are all exactly the same and are the default ones installed.

Answer 1

I did not find an actual cause or solution to this issue but I did find a workaround. Adding the uninstall registry keys to the AllowedPaths entry allowed me to do what I want. Not sure why one server requires this and the other doesn't but I can move ahead this way.