[B]using System.Diagnostics; // Process
using System.Runtime.InteropServices; // DllImport[/B]
//...
// import the function in your class
[DllImport ("User32.dll")]
static extern int SetForegroundWindow(IntPtr point);
//...
Process p = Process.GetProcessesByName([B]"arch" + "eage"[/B]).FirstOrDefault(); [B]//Obscuring to prevent this post from search sites[/B]
if (p != null)
{
IntPtr h = p.MainWindowHandle;
SetForegroundWindow(h);
SendKeys.SendWait("f"); //Put the key you wish here
}