Another problem I've had recently with Vista was that all of a sudden whenever I double-clicked a drive icon in explorer it opened the search panel instead of drilling down into the drive's folders. After digging through google searches here the fix that worked for me:

Open up regedit.exe by using Start\Run and then browse down to this registry key:

HKEY_CLASSES_ROOT\Directory\shell or HKEY_CLASSES_ROOT\Drive\shell

Double-click on the default value and set it to "none" without the quotes, as seen here:

This will restore the normal behavior.