You may have already noticed this and that the drive shows up only when it has something to read in its tray.
If you are wondering the same that how I can make it stay whether it contains DVD or not, i.e. the same style as in XP, here is a quick way of doing so.
1. Open Folder Option by typing in “Folder Option” in search box in Start Menu.
2. Check “Show all folders” option under General tab.
3. As soon as you click on either OK or Apply button, the folder view changes immediately reflecting the change. Now, all my drives show up, including DVD drive that was missing earlier.
Notice that now the style of viewing folder structure at the left panel is exactly the same as before in both XP and Vista.
You may also notice that by default the folder doesn’t expand automatically at the left while navigating through the folders. And that’s exactly what the second option “Automatically expand to current folder” does in Folder Options. Tick it off and click on OK or Apply, you will notice the change in Windows Explorer right away.
That’s it and hope you find this tip useful.