PRB: ExitWindowsEx API Does Not Reboot Windows NT

Back to the top

Step By Step Example

1. Create a new standard EXE in Visual Basic. Form1 is created by default.
2. View the code for Form1. In the Declarations section, add the following code:

         Private Type LUID
            UsedPart As Long
            IgnoredForNowHigh32BitPart As Long
         End Type
   
         Private Type TOKEN_PRIVILEGES
           PrivilegeCount As Long
           TheLuid As LUID
           Attributes As Long
         End Type
   
         Private Const EWX_SHUTDOWN As Long = 1
         Private Const EWX_FORCE As Long = 4
         Private Const EWX_REBOOT = 2
   
         Private Declare Function ExitWindowsEx Lib "user32" (ByVal _
              dwOptions As Long, ByVal dwReserved As Long) As Long
   
         Private Declare Function GetCurrentProcess Lib "kernel32" () As Long
         Private Declare Function OpenProcessToken Lib "advapi32" (ByVal _
            ProcessHandle As Long, _
            ByVal DesiredAccess As Long, TokenHandle As Long) As Long
         Private Declare Function LookupPrivilegeValue Lib "advapi32" _
            Alias "LookupPrivilegeValueA" _
            (ByVal lpSystemName As String, ByVal lpName As String, lpLuid _
            As LUID) As Long
         Private Declare Function AdjustTokenPrivileges Lib "advapi32" _
            (ByVal TokenHandle As Long, _
            ByVal DisableAllPrivileges As Long, NewState As TOKEN_PRIVILEGES _
            , ByVal BufferLength As Long, _
         PreviousState As TOKEN_PRIVILEGES, ReturnLength As Long) As Long
   
   					

3. Add a procedure called AdjustToken with the following code:

         Private Sub AdjustToken()
            Const TOKEN_ADJUST_PRIVILEGES = &H20
            Const TOKEN_QUERY = &H8
            Const SE_PRIVILEGE_ENABLED = &H2
            Dim hdlProcessHandle As Long
            Dim hdlTokenHandle As Long
            Dim tmpLuid As LUID
            Dim tkp As TOKEN_PRIVILEGES
            Dim tkpNewButIgnored As TOKEN_PRIVILEGES
            Dim lBufferNeeded As Long
   
            hdlProcessHandle = GetCurrentProcess()
            OpenProcessToken hdlProcessHandle, (TOKEN_ADJUST_PRIVILEGES Or _
               TOKEN_QUERY), hdlTokenHandle
   
         ' Get the LUID for shutdown privilege.
            LookupPrivilegeValue "", "SeShutdownPrivilege", tmpLuid
   
            tkp.PrivilegeCount = 1    ' One privilege to set
            tkp.TheLuid = tmpLuid
            tkp.Attributes = SE_PRIVILEGE_ENABLED
   
        ' Enable the shutdown privilege in the access token of this process.
            AdjustTokenPrivileges hdlTokenHandle, False, _
            tkp, Len(tkpNewButIgnored), tkpNewButIgnored, lBufferNeeded
   
        End Sub
   
   					

4. Add a CommandButton to the form. In the Click event, add the following code:

         Private Sub Command1_Click()
            AdjustToken
            ExitWindowsEx (EWX_SHUTDOWN Or EWX_FORCE Or EWX_REBOOT), &HFFFF
         End Sub
   
   					

5. Save the project and build an executable. When you run the executable and click the CommandButton the computer will reboot as expected.

Back to the top