After publishing Part 4 of my Windows Vista Installation Super Guide, it occurred to me that one of the features I take for granted in Windows--its Disk Management tool--might be something that most Windows users have never even seen. Disk Management has always been very useful, and the feature I'd like to discuss here--changing drive letter assignments for partitions, media readers, optical disks, and other disks--has been around for quite awhile, and thus most of what I'll discuss here applies equally well to both XP and Vista. But the Disk Management utility gains some key improvements in Vista, including the ability to non-destructively resize partitions. So if you've already created a dual boot configuration with both XP and Vista, for example, you can use Vista's version of Disk Management to alter the partition sizes after the fact if you need to. Nice.

But back to the point of this addendum. One key feature of Disk Management (either version) is that you can use it to change which drive letters are assigned to each disk in your system. This is useful for a number of reasons, but for the anal retentive types--guys like me, sadly--you can use it to ensure that each drive has exactly the drive letter you want. And while this is less important in Vista than it was in previous Windows versions, it's still useful.

Recall my earlier discussion about how the drive letters would be laid out after creating a dual boot system between XP and Vista. In XP, the Windows install would be on the C: drive, while Vista would be on D:, and the optical disk would be assigned to E:. Likewise, if you boot into Vista on the same system, the Windows install would be on the C: drive, while XP would be on D:, and the optical disk would again be assigned to E:. This is very orderly. But what if this isn't what you see? What if, say, the other Windows install is assigned to J: or something because you have a 7-in-1 media reader installed in the system? Or what if the optical drive appears after the logical disks in that media reader? You can use Disk Management to fix this problem.

Note: Technically, of course, this isn't a problem. It's important, especially in XP and older OSes, that the currently loaded Windows install be located on the C: drive because poorly-written software often makes certain disk location assumptions. Again, this is less important in Vista. But if you're anal retentive enough... you know the drill.

Finding Disk Management

In Windows XP, there's really only one fast way to access Disk Management (this works in Vista as well): Open the Start Menu, right-click My Computer (Computer in Vista) and choose Manage. This will cause the Computer Management utility to open. Computer Management is a Microsoft Management Console (MMC) shell that's been preloaded with a bunch of useful snap-ins related to, you guessed it, computer management. One of the snap-ins is for Disk Management, which you can find under the Storage entry in the list of available tools in the left of the console. When you click on Disk Management, you'll see something like this:

 
Windows XP's Disk Manager (left) and the version in Windows Vista (right)

Obviously, the exact configuration will vary from system to system. (And, for what it's worth, the Vista version provides more information and more functionality, such as the aforementioned partition resizing capability, which lets you shrink and expand partitions when possible.)

Using Disk Management to change drive letter assignments

Note that you cannot change (or remove) the drive letter for certain partitions, including those that contain the current operating system's boot files (C:), system volume (the Windows directory, typically on C:), or page files (also typically on C:). In other words, on a typical install, you can't change the drive letter of the C: drive. To change the drive letter for a disk, right-click it and choose Change Drive Letter and Paths. You'll see a dialog like this:


Changing a drive letter assignment.

Here you can choose Add to assign additional drive letters to the current disk, Change to change the drive letter from its current value to one of the unassigned drive letters, or Remove to remove the drive letter from Computer entirely, rendering the disk inaccessible. If you want to change a disk's drive letter, you might need to do some temporary drive letter juggling. Consider the following drive letter assignments on a fictional system:

C: Windows XP (the current OS)
D: Optical disk
E: Windows Vista

In this case, we might want to change the drive letter for the disk containing Windows Vista from E: to D:. However, we can't simply select that disk, right-click it, and choose Change Drive Letter and Paths to do so, because D: is already assigned to the optical drive. So first, we must re-assign the optical disk, temporarily, to F:, then change Windows Vista to D:. Then, we can change the optical drive to E:. When we're done, it will look like this:

C: Windows XP (the current OS)
D: Windows Vista
E: Optical disk

Final thoughts

So there you go. If you really, really want your drive assignments to be a particular way, Disk Management can come in awful handy. Hopefully this addendum will make sense and fill an unclear aspect from Part 4 of the Install Super Guide.