The latest 12/27 PC Magazine has a discussion of a free toolkit from Microsoft that can be used to lock down public and lab computers. This basically sounds like a GUI that allows you to manipulate registry settings.
Microsoft’s free Shared Computer Toolkit lets you configure a PC that can be used to research the Internet, look up resources, and run approved programs; it also stops users from making permanent system changes, running arbitrary programs, or introducing malware… You don’t need an IT degree–the kit leads an administrator through the steps of locking down a system.
The toolkit and documentation are located here.
The toolkit is designed for Windows XP Service Pack 2, and for the NTFS file system. FAT file systems must be converted to NTFS.