HOWTO: Shutdown Windows NT, Windows 95, and 98 from VB Code

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0

SUMMARY

Periodically, you may need to shutdown Windows NT, Windows 95, and Windows 98 from Visual Basic code. The Step-by-Step Example in this article shows how to do this by using the Windows API.

MORE INFORMATION

Step-by-Step Example

1. Start a new Standard EXE project. Form1 is added by default.



2. Add a CommandButton (named cmdForceShutdown) to Form1.



3. Add the following code to the General Declarations section of Form1:
   

   
         Option Explicit
   
         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
   
         ' Beginning of Code
         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
         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
   
         Private Sub cmdForceShutdown_Click()
            AdjustToken
            ExitWindowsEx (EWX_SHUTDOWN Or EWX_FORCE Or EWX_REBOOT), &HFFFF
         End Sub
    




4. On the File menu, click Save Project. Select a folder and a name for your project. Click OK.

REFERENCES

Microsoft Win32 SDK

Additional query words: kbVBp500 kbVBp kbdsi kbDSupport kbNoKeyWord kbVBp600

Keywords          : 
Version           : WINDOWS:5.0,6.0
Platform          : WINDOWS 
Issue type        : kbhowto 

Last Reviewed: May 14, 1999