Error 800 vpn connection

I set up a vpn connection to remote to my desktop at work on both my wireless laptop and home desktop both with Windows XP Prof installed. The laptop and home desktop are on a shared network. I have a 2Wire DSL modem. I can vpn and remote desktop to work with my laptop, but receive the 800 error on home desktop. IP address has been checked and re-entered. Password checked. Firewall settings appear to be the same. Need advice on what to check next.
Thank you in advance for your expert advice.
Barbara