A. There are two ways of doing this (there are more!), one using explorer and one from the command line. Using Explorer

  1. Start Explorer (Win key + E or Start - Programs - Explorer)
  2. Right click on the required folder and select properties
  3. Under the General tab a size will be displayed and this is the total size of the folder and all sub-folders and their contents.

From the command line you can just use the dir command with /s qualifier which also lists all sub-directories, e.g.
dir/s d:\savilltechhomepage
would list all files/folders in the savilltechhomepage directory and at the end the total size.