Oh man, this's one of those Shell issues...
Double-Click My Computer.
Select Tools menu, Folder Options.
In Folder Options, select File Types & wait.
& wait
& wait.
Bag this, get something to drink.
Now that the list is populated, select the
Drive entry.
Click on the Advanced button. This brings up the Edit File Type dialog.
The Edit File Type dialog should show a list of actions (Open, Explore, Find, etc.)that XP can take for this 'file' type.
On my version, XP Pro, I've got two "Drive Information" entries, one "Find", and one "Open Command Window here" entry. And the 'Edit' button is greyed-out.
Use all the info you find in Folder Options/File Types to go search msdn.microsoft.com for a knowledgebase article on how to fix.
I'm afraid it's gonna mean Registry diving.