System.Diagnostics.Process[] processes = System.Diagnostics.Process.GetProcesses();
try
{
   foreach(System.Diagnostics.Process p in processes)
   {
      if(p != null && p.MainModule != null)
      {
         String fileName = Path.GetFileName(p.MainModule.FileName);
         if(String.Compare(fileName, "devenv.exe", true) == 0)
            return true;
      }
   }
}
catch
{
}
return false;