Vista will not allow Drive sharing.
Read Networking XP and Vista info below
http://technet.microsoft.com/en-us/library/bb727037.aspx
Have a read of the above link re Vista File and Printer Sharing.
Permissions/Share info is there as well.
If using Norton, McAfee, Trend Micro I.S., make sure file and printer
sharing is enabled in THEIR firewall (or LAN allowed, depending on how their
Exceptions are worded in their Firewall)
1st thing to do is make sure that the Workgroup Name of ALL the computers is
the SAME.
In Vista Network and Sharing:
Network Discovery: ON (So it can see the other computers)
Network set to Private (Public is for hotspots, airports, etc)
File Sharing: ON
Public Folder Sharing: ON (Vista’s Public Folder is the same as XP’s Shared
Docs)
Password Protected: OFF (unless you want to set up identical usernames and
passwords (passwords can be different) on ALL computers in your Network) If
you have it ON, you will be asked for a username and password when you try to
access a Vista computer from an XP computer, or a Vista computer.