SharpKeys is a utility that manages a Registry key that allows Windows to remap one key to any other key. Included in the application is a list of common keyboard keys and a Type Key feature to automatically recognize most keyboard keys. It was originally developed in C# using .NET v2 but has been updated to support .NET 4.0 Client Profile
Ophcrack is a free Windows password cracker based on rainbow tables. It is a very efficient implementation of rainbow tables done by the inventors of the method. It comes with a Graphical User Interface and runs on multiple platforms.
The HashCheck Shell Extension makes it easy for anyone to calculate and verify checksums and hashes from Windows Explorer. In addition to integrating file checksumming functionality into Windows, HashCheck can also create and verify SFV files (and other forms of checksum files, such as .md5 files). It is fast and efficient, with a very light disk and memory footprint, and it is open-source.