DOS allows certain characters in directory names that are not acceptable to Explorer. Usually this involves inserting one or more characters that created with the ALT key and number sequence in the directory name. Explorer will not open, delete, or rename such a directory. The characters unacceptable to Explorer are 158-159, 169, 176-224, 226-229, 231-240, 242-245, 247, 249, 251-252, 254-255.
The Explorer in Windows NT has no problems accessing such directories.