Kevin,
My first email was regarding the remote Windows PC, not the VPN login. Make sure your logged in on the remote system using exactly the same username and password you would use on a PC at the office.
If your using Windows 95/98, you need to turn on MS networking so your prompted to enter a password at logon. If the user name and password are identical to what you use at the office, it should work. If the resources you seek are on a XP Professional PC, you will run into trouble since you must be a domain user (and authenticated) by default.
good luck,
ryan