If you've got several other users using your PC then it's useful to have some way of limiting or restricting their access to your machine.
Windows has its own profile manager but it's extremely limited in what it can do compared to Windows SteadyState. Windows SteadyState helps you manage Windows XP user profiles in an easy and highly customisable way. In a few steps that you're taken through by Windows SteadyState via a setup wizard, you can create and transfer profiles from one PC to another very easily.
The main benefit of Windows SteadyState is that it lets you restrict the use of the Start menu to open the Control Panel and Network Places so that no damage can be done to your system. With Windows SteadyState, you can also stop them from access the registry in any way or your task manager.
If you're using Windows SteadyState in a company environment, you can also stop employees using the internet and limit access to programs in suites such as Microsoft Office. In addition, Windows SteadyState is a great tool to use an updater - you can schedule it to update aspects of Windows and your profiles so that it's ahead of the latest security threats.
If you're disappointed by Windows profile manager and need a lot more control over who uses your PC, then Windows SteadyState is a solid option.