If you are moving to vBulletin from another type of discussion board, then there is a good chance that you won't want to lose all the posts that you already have and start again with nothing. And it's not just the posts that are important—what about all your member information—usernames, passwords, profile data? You don't want to lose all that and start with a blank forum!
To make migration easier, the vBulletin development team has created a Import/Export script (called the ImpEx script).
ImpEx script is available from the Member Area on the vBulletin site. This means that you need a valid license to be able to download it.
After downloading the script, you will need to extract the files ...