Windows Explorer by default opens with the Documents folder. To change this to open your root drive do the following:

Programs > Accessories.
Right click Windows Explorer and select Send To > Desktop (create shortcut).

Right click the desktop shortcut and in the Target box you should see %SystemRoot%\explorer.exe

Delete that line and replace with: C:\WINDOWS\EXPLORER.EXE /n,/e,C:\ and click apply.

Note: replace the C with the letter of your drive Vista is installed on.

The Windows Explorer shortcut will now expand the root drive.

This also works with previous Windows versions.