Some temp files that have a size of 0 bytes are not deleted automatically after you install or upgrade the printer driver on a Windows Vista or Windows Server 2008-based computer
After you install or upgrade the printer driver on a Windows Vista-based or on a Windows Server 2008-based computer, some temp files that have a size of 0 bytes are created in the following folder:
Note: The temp files have a name, such as BUD
Additionally, these temp files are not deleted automatically.
This problem may occur if the newly installed or upgraded printer driver includes the Unidrv.dll driver for Windows Vista or for Windows Server 2008.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB958708.