Cryogenic FileSplitter is a simple file splitter program with a real easy to use drag and drop interface. You can specify how many sections you want the file to be split into. It also displays each segment size so that you can see how big each segment is going to be before you split it.
Cryogenic FileSplitter is a free portable application and will work on most Windows Operating Systems. I personally tested it on Windows 7 and had no issues.