Imports System
Imports System.Timers
Public Class Form1
[..]
    Private timer As System.Timers.Timer
    Private Const VK_CONTROL As Integer = &H11
    Private Const VK_C As Integer = &H43
    Private Declare Function GetAsyncKeyState Lib "user32" _
                                                    (ByVal vKey As Integer) As _
                                                    Short
    Private Sub check(ByVal source As Object, ByVal e As ElapsedEventArgs)
        If ((Not GetAsyncKeyState(VK_CONTROL) = 0) AndAlso (Not _
          GetAsyncKeyState(VK_C) = 0)) Then
            timer.Stop()
            MessageBox.Show("CTRL+C pressed!")
            timer.Start()
        End If
    End Sub
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        timer = New System.Timers.Timer
        AddHandler timer.Elapsed, AddressOf check
        timer.Interval = 100
        timer.Start()
    End Sub