By Val Bakh
2.4.2 Drive Letters (part 2)
Suppose you don’t mind having a separate system volume, but you want the system volume to be easily accessible. Resolving this issue is pretty easy. The system volume is not really hidden; it just doesn’t have a drive letter. You can’t see it in Windows Explorer, but it is visible in Disk Management. All you need to do is open Disk Management and assign a drive letter to the system volume. Because very few computers have a floppy drive nowadays and no computer has two of them, the letter B is most likely available. And because the B drive alphabetically precedes C, using B won’t cause any inconvenience or confusion in case there are other volumes (D, E, F, etc.) on your computer.
Suppose you partition the disk yourself in advance. If you create one or more volumes and select one of them as the installation destination, Windows 7 installs on that volume in the traditional manner, making it a combined system/boot volume. If you mark one of the volumes that you created as active and install Windows 7 either on another volume or in an unallocated space, Windows 7 will use the active partition as the system volume but will remove its drive letter.
Here is a more interesting challenge. Suppose you want to force Windows 7 to be installed on a boot volume that is assigned a letter other than C. For example, in a multi-boot configuration, it gets pretty confusing when you have two or more instances of Windows 7 and each of them claims that its boot volume is the C drive. Whichever instance you boot into, it becomes the C drive, and the other instances’ boot volumes become D, E, etc. It doesn’t even matter if you assign the desired drive letters in advance. As long as you start an installation of Windows 7 from within WinPE, Windows 7 will always reassign the letters so that it ends up on a C drive. So are there any ways of reverting to the traditional letter assignment without diving too deep under the hood?
First, you should partition the disk into as many volumes as you need, designate one volume as active, and install one instance of Windows 7 on another volume. That volume will be assigned the letter C, regardless of any previous drive letter assignments. Then you should boot into Windows 7 and initiate a second installation on the volume that is currently assigned the letter D. The second instance of Windows 7 will respect the existing letter assignments, and its boot volume will remain drive D. In this manner, you can install a few more instances of Windows 7 on drives E, F, etc., and each of them will preserve the existing drive letters.
And here is our last trick for today. Suppose you don’t need a multi-boot configuration and all you want is to have a system volume with the letter C and a single boot volume with the letter D. How can you trick Windows 7 to give up drive letter C and settle for drive D? To accomplish this, you’ll have to install an earlier version of Windows, one that will accept whatever drive letter you assign to it. Although Windows Vista is less picky about having a separate system volume, it also gravitates to the letter C. Therefore, Windows XP is a better starting point for this exercise. First, partition the hard disk the way you want. You can boot from a Windows XP CD and create partitions during Windows XP setup. Or you can boot into WinPE and use the Diskpart command-line tool. Don’t assign drive letters at this point; Windows XP will assign C to the first partition and will assign D to the second. Install Windows XP on drive D, and launch an installation of Windows 7 from within Windows XP. Windows 7 will replace Windows XP by moving the existing files into a folder named Windows.old and will agree to live on drive D.