HPFS organizes data on hard disks but not on floppy disks (that is, you cannot format a floppy disk to use HPFS). In many cases, accessing files under HPFS is faster than accessing similar files under the FAT file system.
HPFS allows filenames containing as many as 254 characters, including a terminating null. The names can include characters that are not valid for the FAT file system, such as periods. You can use spaces anywhere in an HPFS filename or directory name, but the system ignores spaces and periods at the end of filenames—that is, the filenames Test 1 and Test 1. are treated as if they were the same filename. You can use the following special characters in HPFS filenames:
, + = [] ; _
HPFS filenames do not require extensions, although many applications still create and use them. An HPFS filename can be all uppercase, all lowercase, or mixed-case. The case is preserved for directory listings but ignored in file searches and all other system operations. Therefore, a given directory cannot contain more than one file with the same name when the only difference is case.