The Public folder in Windows Vista is used for sharing folders and files with people on the same computer or the same network. The normal location for the public folder is 'C:\Users\Public', but this isn't necessarily the best location for it, especially if you don't have enough space on your C: drive. With some registry editing, you can move the location of the folder.
First, you should turn on the option to show hidden files and folders in order to make sure you copy all the folders. There are hidden Public Desktop and Favorites folders that need to be copied as well. Next, copy all the folders inside of the current Public folder into a new Public folder.
Click on the Start button and type in 'regedit', then browse to the following key:
In the right pane, double-click on the 'Public' DWord value. Change it the new location where you copied the folder to. Reboot you computer for the changes to take effect. Once you verify the location of the new Public folder, you can simply delete the old one.