You need to change the PATH system variable to include the directory in which you have the executable. This will basically tell windows this: (when the user types in a filename, look for executables in the directories specified in the PATH variable, including this directory).
For windows 7:
Right-click on My Computer => Choose System Properties => Click Advanced System Settings => Advanced tab => Environment Variables , then under System Variables select PATH and click Edit. Add the directory to your desired executable.
For Windows 8:
Control Panel => System => Advanced => Environment Variables , then under System Variables select PATH and click Edit. Add the directory to your desired executable.
Note I: In both cases, if you do not find the item PATH, you may select to add a new variable and add PATH as the name and the location of the class as the value.
Note II: The PATH variable generally looks like this:
C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x86;C:\Program Files (x86)\Intel\OpenCL SDK\2.0\bin\x64;C:\Program Files\Calibre2\;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Windows\SysWOW64;C:\Program Files\Microsoft Network Monitor 3\
To add any new value, insert a semicolon ; followed by the new value (value accepted are obviously absolute paths).