Once you have installed Dropbox, you'll need to know where the Dropbox folder is:
*On Windows XP, the Dropbox folder is located inside the user's "My Documents" folder. The easiest way to reference this is using the environmental variables, as follows: <code>"%
HomeDrive%%HomePath%\My Documents\Dropbox"</code>. Because "My Documents" contains a space, the quotation marks are required.
*On Windows 7 and 8, the default Dropbox folder location is C:\Users\''username''\Dropbox. Use the environmental variables <code>%
*On Linux, the default location is in the user's home folder. For example in Ubuntu, that folder is located at ~/Dropbox
*On Mac OS, it should also be in the user's home folder.
Whichever operating system you are using, Dropbox has very good documentation and can assist you in finding help: http://www.dropbox.com/help