Hi OFSO.
Go to "Folder and search options->View". On Vista and Win 7, it's under the organise menu in any Explorer view. On XP (from memory) it's in the Explorer options menu.
Select "Hide Empty Drives in the Computer Folder"
This sets the drive to hidden so, if you are also viewing hidden files, the drives will still appear but will be greyed out.
Despite the stupid flame wars, this is by design for rapid remounting of drives and compatability with old pre-XP apps which could not handle drives disappearing. The hidden files option read "files, folders or drives".
Hope this helps
Cheers
Mad jock. The problem is not with Windows. It's with the ill qualified people working as "admins". I cannot think of anything that needs a visit to a Win box except "not bootable", which of course applies equally to *nix boxes. No need for telnet either, thankfully, but of course you can use it if you want to.
PS. Nix admins never leaving their offices probably explains why they have such a poor customer facing reputation