Hey, they're called switches - they're extra parameters that make the command do a more specific and targeted job (given what the above switches for this command mean below) /D:m-d-y Copies files changed on or after the specified date. If no date is given, copies only those files whose source time is newer than the destination time. (His suggestion contains no date so all files in that directory - and sub directories (even if empty 'cause of /E) are copied over if newer than the versions in the place they're being copied to.) /E Copies directories and subdirectories, including empty ones. Same as /S /E. May be used to modify /T. /C Continues copying even if errors occur. /R Overwrites read-only files. /I If destination does not exist and copying more than one file, assumes that destination must be a directory. /K Copies attributes. Normal Xcopy will reset read-only attributes. /Y Suppresses prompting to confirm you want to overwrite. Windows Vista has tried to replace this with Robocopy (Robust File Copy for Windows), but xcopy will still work :)