running exe file

This is really a question for the .NET Programming forums, Mohamed, but no matter :)

To run an .exe file from a .NET program, you need to be looking at the System.Diagnostics.Process class. Here's a quick example in C# :

Process proc = new Process();
proc.StartInfo.FileName = @"C:\myprogram.exe";
proc.Start();
proc.WaitForExit(); // if you want to wait until the executable has finished running

There's a lot you can do with the Process class, including passing command line arguments to the executable, and I'd have a read through the documentation if your needs are more sophisticated than the above example:

http://msdn2.microsoft.com/en-us/library/system.diagnostics.process(vs.80).aspx