The .NET Framework Software Developer's Kit (SDK) is available as a free download from Microsoft's web site: http://msdn.microsoft.com/library/default.asp?url=/downloads/list/netdevframework.asp.
Since URLs and links are continuously changing, the directions for finding the proper location within Microsoft's domain may change after this book is published; please check for updates to these instructions on the Apress web site (http://www.apress.com).
Among other things, the SDK comes with
A command-line C# compiler (csc.exe)
The common language runtime (CLR), the engine that runs compiled C# programs
A wide variety of utility tools, including a runtime debugger
Complete documentation for everything in the .NET SDK, including the contents of the .NET Framework Class Libraries and much more.
You must download two separate sets of software to get C# and .NET running on your machine:
First, download and install the .NET Framework Redistributable package. This package contains the CLR and other .NET Framework components that are needed to run .NET Framework applications. The Windows 98, Windows Me, Windows 2000, Windows XP, Windows NT, and Windows Server 2003 operating systems all support the .NET Framework Redistributable package.
After the .NET Framework Redistributable package is installed on your machine, download and install the .NET Framework SDK. The SDK contains everything you will need to write, compile, test, and deploy C# applications, including documentation, libraries, compilers, and command-line tools. You must be running one of the "newer" versions of Windows—at least Windows 2000,Windows XP, or Windows Server 2003—to install the .NET Framework SDK.While it's possible to run C# applications under "older" versions of Windows—e.g., Windows 98, Windows Me, or Windows NT—you can't develop such applications on these platforms.
Follow the instructions provided by Microsoft for installing both the Redistributable package and the SDK on your particular system.