Using compression is the single most effective way to reduce page load times. The .aspx files sent by the server to the browser consist of HTML. HTML is highly compressible by algorithms such as gzip. Because of this, modern web servers including IIS 5 and later have the ability to compress outgoing files, and modern browsers have the ability to decompress incoming files.
Both IIS 6 and IIS 7 offer advanced compression related options that help you get better performance improvements for your web site and make better use of your servers and bandwidth. Unfortunately, these options are not always easy to access. This article series shows step by step how to unlock these options.
In the first article in this two part series, we’ll focus on configuring IIS 7 compression. If you are used to IIS 6, you’ll find that IIS 7 offers many new features, including the ability to cache not only compressed static files, but also compressed dynamic files. If you still use IIS 6, the next article in the series will show how to configure IIS 6 compression.
This article is based on chapter 10 Compression of my book ASP.NET Site Performance Secrets.
Read Full Article : Configuring IIS 7 compression By Matt Perdeck
Hope this will help !!!!!