Here is something you may have experienced already: As a newcomer on an existing project, you check out the code from source-control and discover that the build is broken. When you ask around no-one else seems to have that problem but a helpful collegue is kind enough to tell you that you can find the installers for the missing dependencies at location X (Let’s not even mention the places where those installers are not available *sigh*).
Anway, in order to avoid such a situation you could organize your solution in such a way that all the dependencies (libraries and tools) are part of it. A typical folder structure would look like this:

In order to get those files out of the installer and in your solution (instead of installed under %Program Files%) you could do an administrative install of the msi (eg: msiexec /a Blah.msi) but i find it easier to use Qwerty.Msi.
Here are a couple of settings you may want to add to your build configuration in order to make your self-contained build work:
<!-- Configure solution directories --> <basePath Condition="'$(BasePath)'==''">$(MSBuildThisFileDirectory)..</basePath> <buildPath>$(BasePath)\build</buildPath> <sourcePath>$(BasePath)\src</sourcePath> <toolsPath>$(BasePath)\tools</toolsPath> <!-- Configure tool directories --> <!-- the ending \ is required for the extension pack --> <extensionTasksPath>$(ToolsPath)\MSBuild.ExtensionPack\</extensionTasksPath> <msbuildCommunityTasksPath>$(ToolsPath)\MSBuildCommunityTasks</msbuildCommunityTasksPath> <ilmergeToolPath>$(ToolsPath)\ILMerge</ilmergeToolPath> <svnToolPath>$(ToolsPath)\Subversion\bin</svnToolPath> <!-- wix will use this property to determine the location of other files --> <wixToolPath>$(ToolsPath)\Wix</wixToolPath> <!-- Configure target file paths --> <commonTargetsPath>$(BuildPath)\common.targets</commonTargetsPath> <msbuildCommunityTasksTargetsPath>$(MSBuildCommunityTasksPath)\MSBuild.Community.Tasks.Targets</msbuildCommunityTasksTargetsPath> <extensionPackTargetsPath>$(ExtensionTasksPath)MSBuild.ExtensionPack.tasks</extensionPackTargetsPath> <!-- Configure WIX --> <wixTargetsPath>$(WixToolPath)\Wix.targets</wixTargetsPath> <wixTasksPath>$(WixToolPath)\WixTasks.dll</wixTasksPath> <wixTargetsPath>$(WixToolPath)\Wix.targets</wixTargetsPath> <wixTasksPath>$(WixToolPath)\WixTasks.dll</wixTasksPath> <luxTargetsPath>$(WixToolPath)\Lux.targets</luxTargetsPath> <luxTasksPath>$(WixToolPath)\LuxTasks.dll</luxTasksPath> <luxTargetsPath>$(WixToolPath)\Lux.targets</luxTargetsPath> <luxTasksPath>$(WixToolPath)\LuxTasks.dll</luxTasksPath>
With this solution in place the next ‘new guy’ does not have to waste time trying to figure out where those dependencies are