You have seen a file named "AssemblyInfo.cs (or .vb according to your programming language)" in your projects. This file contains information about the output assembly of your project such as Author's Name, Copyright Notice, ... and Assembly Version. By default assembly version is set to 1.0.0.0. This version declaration shows major.minor.build.revision numbers of your assembly. Two first numbers are commonly constant e.g. 2.0. Third number follows YYMMDD rule (of build date) and the last number is build counter.

It is a good idea to change assembly version and use it in your application. For example you can show Application Version to the end user. It's so easy, take a look:

Assembly assembly = Assembly.GetExecutingAssembly();
string version = assembly.GetName().Version.ToString();

 But one thing that I was interested in was "How to tell Visual Studio 2005 change assembly version in an auto increment behavior?"

After I googled this issue I found a solution on MSBuild Team Blog. They built an AssemblyInfoTask on GotDotNet.com. It's so easy to be integrated in your project. Just download the required package and run it. It will install AssemblyInfoTask in your GAC or Application Data folder (depending on your choice). Then you should add this single line of code to your project file after last <Import> tag:

<Import Project="$(MSBuildExtensionsPath)\Microsoft\AssemblyInfoTask\Microsoft.VersionNumber.targets"/>

or this one (if you installed it in Data Application folder):

<Import Project="$(APPDATA)\Microsoft\MSBuild\AssemblyInfoTask\Microsoft.VersionNumber.Targets"/>

Everything is done now! Your Assembly Version will change automatically based on the rules I said before.

Because Setup file and updated help file of this project are located on GotDotNet.com and you should login to this site and also join this project to download them, I uploaded Setup package and updated Help file for you. Find them below:

Downlod: Setup Package | Updated Help File