Note: This is an old driver for Windows XP and Windows 2000. It has not been updated for later versions. For a more recent option, try the Nero Platinum Suite.
The wnaspi32.dll file represents an ASPI (Advanced SCSI Programming Interface) driver which allows burning softwares to recognize ANT to handle CD/DVD burners. WNASPI can only be copied in the application directory, but not in a system directory.