In Team Foundation Server 2008 you could delete builds both from the Build Explorer, using the context menu on one or more builds, and from the command line, using TfsBuild.exe. Also, retention policy would automatically delete builds as specified. Once you deleted the build, you no longer were able to see the build in the Build Explorer, as it no longer "exists", and TfsBuild.exe's delete command will complain that the build doesn't exist. In Team Foundation Server 2010, you may be surprised to find that, although you don't see the build in Build Explorer, your data still exists in the database. Well, some of it.