Although windows has predefined configuration for Internet protocols, but there are some registry hacks which can be used to optimise the windows settings for a particular Internet connection to get the optimal speed over a particular connection. Internet Cyclone 2.13 claims to boost the Internet speed up to 200%.
This software optimizes the windows settings and thus the optimized configuration is effective on all applications and browsers, including Internet gaming, video chats and all other Internet specific tasks.
Obviously it is not going to make your 1Mbps broadband connection a 2MBps connection. If your Internet connection speed is 1Mbps, it will allow you to use it with the best performance.
Developer Site : http://www.jordysoft.com/icyclone/internet-cyclone.aspx