I developed a simple utility that offers a “right-click and hash” interface for calculating MD5, SHA-1 and SHA-256 hashes of files.
The app is written in C++, with ATL, WTL and some STL and Boost. (The CRT is statically linked, so there is no need to download Visual C++ run-time redistributables and install them. The all-in-one installer is just a couple of hundreds of kilobytes .exe.)
I tested the app with both Windows 7 64-bit and Windows XP SP2 32-bit, and it seems to work correctly. (However, note that SHA-256 isn’t available on XP SP2.)
Installers for both 32-bit (x86) and 64-bit (x64) versions are attached to this blog post.