Windows Command Reference Download
A nice little download from Microsoft:
Download details: Windows Command Reference
Its a help file (chm) with details on most Windows Vista / 7 / 2008(R2) command line programs and their syntax.
The Windows command-line tools are used to perform various tasks related to Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows 7, and Windows Vista. You can use the command reference to familiarize yourself with new and enhanced command-line tools, to learn about the command shell, and to automate command-line tasks by using batch files or scripting tools.