Binary file generated by the Windows operating system when sending documents to the printer in Microsoft Windows 2000 or XP; increases the spooler efficiency of the print driver; most often created from .GPD files so when the GPD parser is updated, the associated BUD file must be regenerated.

Most users will only see this file because they have encountered a printing error. The error usually occurs after they install a new OEM printer driver, service pack that updates the Unidrv.dll file, system update, or printer hotfix on a server in Windows 2000 or Windows 2003 server. The BUD file must be given time (up to several hours) to successfully regenerate or else the user may receive a message that says the print queue is full when they're trying to print something.