I can successfully kill processes using API calls.

I am now trying to terminate a SYSTEM process, but my attempts to kill it fail. OpenProcess returns Access Denied.

I can kill this system process by using the TaskManager and choosing “End Process”.

What am I missing to make OpenProcess work?

Thank you.

Here is my entire code:

Public Sub KillProcess(ByVal uProcID As Long)

    pGiveThisAppKillPrivilege

    Dim lHandle&
    lHandle = OpenProcess(SYNCHRONIZE Or PROCESS_TERMINATE, ByVal 0&, uProcID)
    
    If lHandle = 0 Then
        Debug.Assert False
        MsgBox "Dll Error " & Err.LastDllError & " occured while trying to open process."
        Exit Sub
    End If
        
    Debug.Print Err.LastDllError
        
    If lHandle = 0 Then
        Debug.Assert False
        MsgBox "Error finding target process handle"
        Exit Sub
    End If

    ' Terminate the process.
    If TerminateProcess(lHandle, 0&) = 0 Then
        Debug.Assert False
        MsgBox "Error terminating process"
    Else
        MsgBox "Process terminated"
    End If

    CloseHandle lHandle
    
End Sub
Private Sub pGiveThisAppKillPrivilege()

   Dim hdlTokenHandle As Long
   Dim tmpLuid As LUID
   Dim tkp As TOKEN_PRIVILEGES
   Dim tkpNewButIgnored As TOKEN_PRIVILEGES
   Dim lBufferNeeded As Long
   
   Dim lHandleOfThisProcess As Long
   lHandleOfThisProcess = GetCurrentProcess()
 
    Dim lRet&
    lRet = OpenProcessToken(lHandleOfThisProcess, (TOKEN_ADJUST_PRIVILEGES Or TOKEN_QUERY), hdlTokenHandle)
 
    If lRet = 0 Then
        Debug.Assert False
        MsgBox "Could not OpenProcessToken! Error: " & Err.LastDllError & ", lret: " & lRet
        Debug.Assert False
        Exit Sub
    End If
 
   LookupPrivilegeValue "", "SeDebugPrivilege", tmpLuid
   tkp.PrivilegeCount = 1    ' One privilege to set
   tkp.TheLuid = tmpLuid
   tkp.Attributes = SE_PRIVILEGE_ENABLED
   ' Enable the kill privilege in the access token of this
   ' process.

   lRet = AdjustTokenPrivileges(hdlTokenHandle, False, tkp, Len(tkpNewButIgnored), tkpNewButIgnored, lBufferNeeded)
    If lRet = 0 Then
        Debug.Assert False
        MsgBox "Could not AdjustTokenPrivileges! Error: " & Err.LastDllError & ", lret: " & lRet
        Debug.Assert False
        Exit Sub
    End If

End Sub