You should just use the forms KeyUp event, something like this
public Form1()
{
InitializeComponent();
this.KeyUp += new KeyEventHandler(Form1_KeyUp);
}
void Form1_KeyUp(object sender, KeyEventArgs e)
{
if (e.Control && e.KeyCode == Keys.Tab)
{
button1_Click(sender, null);
}
}
private void button1_Click(object sender, EventArgs e)
{
MessageBox.Show("You pressed Ctrl + Tab");
}
Hope this helps