You can open your help file with the Process
class... view the Process Class page at MSDN for more information:
Process.Start("help.chm");
For this to work, you will need to place the 'help.chm' file in the 'bin' folder where your executable is. You could put this file elsewhere as long as you use the correct relative path from your application executable file to it. You will also need to add the following:
using System.Diagnostics;