How to use Drupal Code Sniffer in windows?
On the project page there are instructions for each IDE.

The one you're after (Eclipse) is here.

In case anyone uses something else, the other instructions are as follows:

Vim, Sublime Text, and Komodo

Netbeans

PHPStorm (install the Codeing Standards globally first, as described here, then Drupal should be available in the list or rulesets.

You won't get this working in Notepad.  

On another note, I'd probably also just stop using Notepad.  If you must use a basic tool, then Notepad++ is a million times better.