vBulletin Manual - When Pictures are in the File System

When pictures are in the file system, you have several options:

Move pictures within the file system - this option allows you to move the pictures to a different directory in the file system. Select this option and then enter the new paths on the following screen.
Note:
This step does not create the new directory, nor does it actually move the pictures. It simply changes the directory that vBulletin looks for pictures in. You must create the directory, give it proper permissions (as detailed in the previous section), and then move the pictures manually.
Keep pictures in the file system, but disallow direct access to thumbnails - this simply moves the thumbnails so they are no longer directly accessible. This process is similar to moving the pictures into the file system, so see this section for more information.
Move pictures into the database - this returns the pictures to the database. It is similar to the process for moving the pictures into the file system, so see this section for more information.