Invoke-Command -ComputerName windows-host -ScriptBlock { Get-CimInstance Win32_OperatingSystem } Instead of omi new , use the underlying WQL interface:
# Stop WMI service net stop winmgmt /y ren %windir%\System32\wbem\Repository Repository_old Restart WMI (it rebuilds the repository) net start winmgmt Re-register all WMI classes cd %windir%\System32\wbem for /f %s in ('dir /b *.mof') do mofcomp %s win32operatingsystem result not found via omi new
omi new root/cimv2 Win32_ComputerSystem If this does return a result, the problem is specific to Win32_OperatingSystem . If it also fails, the issue is broader (namespace, permissions, or WMI corruption). Log on to the Windows machine directly (or via RDP) and open PowerShell as Administrator : By default, Win32_OperatingSystem lives in root/cimv2
# Allow WinRM (HTTP) – port 5985 New-NetFirewallRule -DisplayName "WinRM HTTP" -Direction Inbound -Protocol TCP -LocalPort 5985 -Action Allow Enable-NetFirewallRule -DisplayGroup "Windows Management Instrumentation (WMI)" OMI Server Permissions (Least Privilege Gaps) The OMI
The most common root causes, ranked by frequency: OMI on Windows typically maps to WMI namespaces. By default, Win32_OperatingSystem lives in root/cimv2 . However, if your OMI client is configured to use a different namespace (e.g., root/default or root/omi ), the class will not be found. 2. OMI Server Permissions (Least Privilege Gaps) The OMI server authenticates the user but then impersonates that user to access WMI. If the user lacks DCOM/WMI permissions or is not part of the local OMI Users group, the WMI query may return an empty result set silently. 3. Corrupted WMI Repository If WMI itself is broken on the target Windows machine (e.g., after a failed update or manual registry tampering), even local wmic os get commands fail. OMI, being a wrapper, inherits this corruption. 4. OMI Server Not Running as SYSTEM The OMI service ( omiengine ) must run with sufficient privileges (Local System) to access all WMI namespaces. If it is running as a lesser account, queries to security-sensitive classes like Win32_OperatingSystem may be suppressed. 5. Firewall or WinRM Blocking Internal WMI Calls OMI on Windows uses WinRM or DCOM internally to bridge to WMI. If WinRM is disabled or the firewall blocks high-numbered RPC ports, the OMI server cannot complete the request. Step-by-Step Diagnosis Before attempting fixes, gather diagnostic data. Run these tests from the OMI client machine. Step 1: Verify Basic OMI Connectivity # Using omicli (where available) omicli id If this fails, check network connectivity and port 5985/5986. Step 2: Isolate the Query Syntax Ensure your omi new syntax is correct:
: On the Windows target, run as Administrator: