Have you ever noticed that Windows XP gives you the 'yes to all' option in its file copy dialog box, useful if you would like to overwrite files in a directory with newer files of the same name from another location, for example, but fails to offer a 'no to all' option for doing the opposite. Kind of annoying if you think about it. What if you have a lengthy file copy operation partially finished, and wish to restart it? If you use the default options, you essentially have to recopy every file, since saying 'no' to each and every duplicate file will take just as long, and cause your mouse finger to fall off.
Fortunately, there is a way to tell your computer not to copy all duplicated files with a single command:
To do this, when the file copy dialog box appears asking you whether you wish to overwrite the first file, hold down SHIFT and click 'no.' This will automatically answer no for all following files. Note that it will ask you again for the first folder it encounters, so follow the procedure again to answer no automatically for all folders. This will dramatically speed up the file copying process.