If these OSes are installed on FAT16 or FAT32 partitions I have discovered (from much experimentation) that if the "long" file (or folder) name is (a) 8.3 compatible AND (b) does not contain mixed case letters (in either the name or the file extension) then a DOS-alias is not created.
Thus the folder Desktop creates a DOS-alias but WINDOWS or myfolder or myfile.TXT do not, since they have the same case throughout the filename and/or the file-extension - even if the name and the extension are themselves of different case.
On NTFS partitions it is similar but the mixed case no longer affects the outcome.
There must be some information on this somewhere but I'm darned if I can find it!
Have tried all the settings at HKLM\SYSTEM\CurrentControlSet\Control\FileSystem to no avail: setting Win31FileSystem to true creates 8.3 dos thoughout but no longnames of course.
The same files created in Win9x/ME on FAT32 partitions always show both short and long formats when viewed using dir /x in Win2K/XP so there must be a place allocated to them in the FAT entries/attributes.
Why is this a problem? Well, in the absence of a short name, when the long name is 8.3 compatible, then the same files are all converted to upper case when viewed from Win9x/ME on a multi-boot system.