As many other people, I installed Windows Vista on my system but I decided to keep Windows XP for gaming and other tasks which, at least for now, work better on XP. When you have multiple partitions and hard disks, one of the challenges of having a dual boot system is keeping the same drive letters in both operating systems.

When I installed Windows Vista for the first time I did not pay attention to this detail and had them assigned in a confusing way. In Windows XP, the "cinema" partition had the letter G: and in Windows Vista "H:", while the "lavoro" (work) partition had the letter "D:" in Windows XP and "E:" in Windows Vista.

That confused not only myself but also the other users that worked on the same computer. So... what can you do to avoid such a scenario?

Learn how to assign your drive letters in a dual-boot configuration

When you decide to have a dual-boot configuration you should reserve two partitions (and two drive letters) for the operating systems. Windows XP will be placed on the drive with the letter "C:". When you install Windows Vista and log in, it will see itself as being installed on "C:" and Windows XP on another partition. The "problem" is that, while you can change the drive letter for the Windows Vista partition when you are in Windows XP, when you are in Windows Vista you cannot change the drive letter assigned for the XP partition.

It will always give you an error message saying: "Windows cannot modify the drive letter of your volume. This may happen if your volume is a system or boot volume, or has page files".

In this case you should write down the drive letter for the XP partition that was assigned in Windows Vista. Then you should boot back to Windows XP and change the drive letter for the Windows Vista partition to the same letter.

For example, if in Windows Vista, the XP partition has the letter "D:", then you should boot in Windows XP and assign the letter "D:" to the Windows Vista partition. Now, depending on the operating system you boot in, the letters "C:" and "D:" will represent the operating systems.

For the rest of your partitions you can change the drive letters and assign them in the same way for both operating systems. This way you will always know where your work, music or games are stored and you won't get confused every time you boot to a different Windows operating system.

How to change a drive letter in Windows Vista

Close all running applications, go to Control Panel and then to System and Maintenance. Now click on Administrative Tools.

From the list of available tools, double-click on Computer Management.

If you are using the Classic View for the Control Panel, just go directly to Administrative Tools and there you will find Computer Management.

Computer Management has several sections. Go to Storage and click on Disk Management.

You will see a list with all the hard disk drives and all the partitions. Right-click on the partition you want to change and select Change Drive Letter and Paths.

In the Change Drive Letter of Path window select the new drive letter that you want to assign and click on OK.

Now you will receive a warning like the one below. Click on Yes and the drive letter will be changed.

How to change a drive letter in Windows XP

The procedure is identical to the one for Windows Vista. Just go to Control Panel - Administrative Tools - Computer Management. From there you follow the same procedure and you are done.

Final Comments

If you follow this procedure, you should have the same drive letters for all your partitions except the ones where the operating systems are installed. For example, in Windows XP, you will see XP on drive "C:" and Windows Vista on drive "D:" and in Windows Vista you will see XP on drive "D:" and Windows Vista on drive "C:".

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How to install Windows Vista
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