Hi, KRK.
It's part history, part operating system - and part controllable by you.
In the olden days (in 1977, when I got my first TRS-80), there were NO disk
drives. Then we got a single floppy drive, which became Drive A:. Then we
added a second floppy, Drive B:. My computer grew to 4 floppies, but 2 was
the standard. And then came those humongous 5 MB hard drives! MS-DOS
(Microsoft DISK Operating System) reserved the A: and B: for the standard 2
floppies and assigned the letter C: to the hard drive. And that's the way
it was for a few years.
And then we went wild! We learned to divide a single hard disk into
multiple partitions. Rather than call them Partition C: and Partition D:,
the DOS called them Drive C: and Drive D: - and the name still sticks today,
inviting confusion. The letters C:, D: - and X: - do not apply to the
entire physical drive, but to a partition on the drive, even if there is
only a single partition and it includes the entire drive. Then we added a
second HDD - and maybe more - and partitioned them and assigned "drive"
letters to those partitions. And optical drives, first CD and then DVD;
these usually used disks with only a single partition, but multiple
partitions on these disks are quite possible and sometimes exist.
And then came USB, with its flash drives and card readers and other devices,
along with network drives, and all of these are eligible to be assigned
"drive" letters.
Left to its own devices, Windows Vista Setup assigns the letter C: to its
own "boot volume" and then assigns the letter D: to the "system volume", if
it is not the same as the boot volume. (See KB314470
(
http://support.microsoft.com/default.aspx/kb/314470) for the
counterintuitive definitions of these two terms, "system volume" and "boot
volume"; it is very important to get them straight in your mind.) After
that, it assigns letters to other partitions and devices, generally in
sequence, but with certain exceptions built into the operating system. The
boot and system volume letters are assigned at the beginning, by Setup.exe,
and can't be changed except by running Setup again - that is, by
reinstalling Vista.
All the other drive letters can be assigned and reassigned by an
Administrator. Just run the built-in utility, Disk Management. (There are
several ways to launch Disk Management; I prefer to press Start, type
"diskmgmt.msc" and press Enter.) Here, after studying the layout for a few
minutes, it becomes pretty obvious how to do most jobs. To change your USB
stick from D: to U:, for example, just right-click on Drive D: and choose
"Change drive letter and paths..." The Wizard will guide you to select from
the list of unused letters. Once you've "vacated" the letter D:, you can -
if you choose - right-click on your Drive E: and change it to D:. (There is
no requirement to use them in sequence, so I like to choose mnemonic letters
to help me remember.)
In the top part of Disk Management (the Volume List), widen the Status
column so that you can read it, then look for the labels "System" and
"Boot". There should be ONE of each and they MAY both be on the same
partition. The letter or letters for these partitions cannot be changed,
but all the others are fair game. Once you have explicitly assigned a
letter in Disk Management, the system will attempt to use that same letter
each time you plug in your USB drive or other device, rather than simply
assigning "the next available letter" each time.
Disk Management was introduced in Windows 2000, almost 10 years ago, and it
quickly became one of my favorite features.
RC
--
R. C. White, CPA
San Marcos, TX
(e-mail address removed)
Microsoft Windows MVP
Windows Live Mail 2009 (14.0.8064.0206) in Win7 Ultimate x64
