@FSTYPE

@FSTYPE[d:]:  Returns the file system type for the specified drive. 
 @FSTYPE will return "FAT" for a DOS-compatible drive with a file 
allocation table, "HPFS" for a drive that uses OS/2's high performance 
file system, or "CDFS" for a CD-ROM drive.  It may return other values if 
additional file systems have been installed with the IFS= directive in 
CONFIG.SYS.