If you still want the project to be available, someone could simply block the project to prevent registration and verification. It will remain locked by the user, which locks it until the user unlocks it or their workspace is deleted. An administrator can also unlock it using tf.exe.
You can lock a project, branch, folder or file by right-clicking on it and choosing the Lock option in the context menu (note: what you are blocking to physically exist on your disk). This page describes the various types of locks that you can place on an element.
, . , TFS ( - Network Service). , - tf.exe, .