With .NET things have gotten much simpler. The System.Diagnostics namespace exposes
a Process class that you can use to launch external programs. At the simplest level,
you can launch a new process with the shared Process.Start method, passing it either
the name of an executable file or a filename with an extension associated with an
executable application. For example, the following code launches the “c:somepathsomefile.txt”

 System.Diagnostics.Process.Start
_ ("c:somepathsomefile.txt") 

Launching and Monitoring
External Programs from VB.NET Applications

Link
here