The way that CP/M and MS-DOS originally assigned drive letters was simple.The drive you booted from was the first, so it was called A. But floppy drives were expensive and hard drives were very expensive, so in the late 1970s when this stuff was standardized, most machines only had a floppy drive or 2.Alternate drive letters for the primary hard disk is something that almost no one tests for, and so you'll end up finding subtle breakage in lots of places.Tags: Essay About Long Lasting FriendshipEssays On RebeccaEthnography EssayLaw Essays Common LawGood College Essay ResponsesProblem Solving For Toddlers
Other than drive C: there is no guarantee that a drive letter will be present, permanent or writable.
To a certain extent the whole concept of drive letters is redundant.
O/S such as Home Server from Microsoft simply aggregate the available disk space together and use raid-like techniques to ensure that if any physical device fails you won't lose any data.
I'd say the primary reason we're stuck with it in Windows is that Microsoft doesn't want to break all the software that is written to expect things this way.
Windows NT copied the patterns of MS-DOS, because DOS was the dominant OS when NT was launched in 1993.
(PC DOS is just IBM’s brand of MS-DOS.) See the answer about Apricot computers for how (some) non-IBM-compatible DOS computers assign drive letters.You can survive doing it otherwise, but you'll regularly run into annoying problems.You would be amazed at how many freshly developed, "cutting edge" applications assume c:\ to be the primary hard disk.So, you copied from A: to a the virtual drive B: and the OS prompted you to swap disks as necessary.Floppy drives got cheaper, and it became common to have two. This was very common as up to and including MS-DOS 3.3, DOS only supported partitions of up to 32 MB.If you only had 1 drive, which was common, then the OS called it both A and B.This is so that you could copy files from one disk to another; otherwise there would be no way.Use drive letters C through Z for hard disk drives.Drive letters A and B are reserved for floppy disk drives.So, all the answers that say that “certain drive letters are reserved for floppies” are wrong. If you had a floppy and a hard disk, then if you booted off the floppy, the floppy drive was A and the hard disk was B. It is a convention that A was the first floppy and C was the first hard disk, and everything else was assigned at boot time. Earlier versions of NT still sequentially assigned drive letters in the same way as DOS and thus Win9x, as did OS/2.If you booted off the hard disk — and early hard disks were often not bootable — then the hard disk became A and the floppy became B.