In windows if you list directory and files with DIR command in MS Dos prompt then you will get the list of files and directory with long names including spaces and when you want to change the directory with CD command to get into that directory then you may can get error.

Below is the screen shot if you give DIR command:

To get the short names for files and directories in 8.3 name format in windows give Dir command with X parameter e.g. Dir /x as shown below:

Like for directory Program Files (x86) the short name is Progra~2.