Elenarie: I dunno why you would mention FAT or FAT32 nowadays. It wasn't relevant back in 2001 when XP was released, and it is not relevant today either.
It's not as relevant today for PC's, but it is for other devices. MP3 Players might still make use of FAT16/FAT32 for simplicity. I think i have a few external drives that are FAT32, i just don't have huge individual files. But that would be my 300Gb or smaller drives...
Elenarie: One thing I should mention about extending volumes is that the space that you're expanding to has to be continuous <snip> But I am not sure if this is a Windows only thing or a file systems in general thing.
In theory the OS could take the whole area including what's used, and then just mark that area as used with a filename attached to it with a big fat
DO NOT DELETE/USE option, or mark it as bad sectors.
And it's more Windows than anything else. Since Windows is based on it's
MS-DOS roots of using letters for drives, you force separation, while in Unix environments you mount it to the root somewhere, letting you swap out one drive for another, or expand an area while being transparent otherwise. More recent versions of windows do seem to have a mounting option for directories, but i haven't gotten it to work, and i'm not fighting too hard to figure it out either.
Maybe it's also related to the basic
IDE hardware most systems came with which was cheaper than
RAID or
SCSI;
RAID has an option where it will append one drive/partition to another letting you expand the drive's capacity as a whole. Sounds cool, but it really depends on the use.