check if application duplicate

hi again,
i know i've been posting alot today, but i am close to finishing my first .net application so i need to put in a few final touches.
how can i allow windows to run only one 'instance' of my program? that is, while program running, user cannot execute exe file of the program....

thanks

Try searching for 'single instance' on this forums. This question comes up frequently. In fact you should always try a search before posting if you want to save sometime. Lastly if you find multiple examples pick the one that uses a Mutex it'll be faster. In fact here I'll do the search for ya: http://www.vbforums.com/search.php?s...der=descending

lol thanks

This was copied from VBCodeBook , you know that guys ;)

VB Code:

Check for multiple instances of a program and ask the user if he / she wants to run another copy.
   
    'Create a new instance of your main form
    Dim MainForm As New Form1()
 
    Private Sub MultiCheck()
        'Get number of processes of you program
        If Process.GetProcessesByName(Process.GetCurrentProcess.ProcessName).Length > 1 Then
            'Ask user if they want to run another copy
        If MessageBox.Show("There is already a copy of this program." & vbCrLf _
            & "Do you want to launch another?.", _
            "Launch another copy of this program?", _
            MessageBoxButtons.YesNo, MessageBoxIcon.Question, _
            MessageBoxDefaultButton.Button1) = DialogResult.No Then
            'If no, then exit the new instance of the program
                Application.Exit()
                Exit Sub
            Else
            'Else run the new program
                MainForm.ShowDialog()
                Exit Sub
            End If
        End If
        'If this is the only one, run it!
        MainForm.ShowDialog()
    End Sub

I used to use that same process but the Mutex way is much faster, like 10 times faster.