Vista file sharing over networks is still poor, but usable if you persevere. However sharing the root of a drive isn’t an option (in my case an external usb hd), unless you add Everyone to the drives security permissions. Do the following:
- Right click on drive, go to Properties
- Click security tab
- Click Edit
- Click Add
- Enter Everyone in the input box, click Check Names, then OK.
- Select Everyone, then give the user the permissions you want.
- Ok your way out.
Now you need to go to Properties again, to the Sharing tab, then Advanced Sharing. The normal share button is still greyed out, but the advanced share should work anyway.