using System.Diagnostics;
var process = Process.GetCurrentProcess(); // Or whatever method you are using
string fullPath = process.MainModule.FileName;
//fullPath has the path to exe.
There is one catch with this API, if you are running this code in 32 bit application, you’ll not be able to access 64-bit application paths, so you’d have to compile and run you app as 64-bit application (Project Properties → Build → Platform Target → x64).