TCP Optimizer 

Product: TCP Optimizer 2.03
Company: speedguide.net 
Website: www.speedguide.net
Type: Free
Requirements: Windows 2000/XP

TCP Optimizer is a program for tweaking broadband-related Registry settings. Optimise Dialup, DSL and Cable all from one simple to use interface. (It has the option to return your Registry to its default untweaked state as well) It also includes built-in MaxMTU and Latency(Ping) detection utilities.