Help!!! Can’t install Cisco VPN on WXP

I have an end user whom I am attempting to get set up with VPN access from home. He is running Windows XP. We use the Cisco VPN client. Anythime he attempts to load the CPN client he gets a message that states “Cisco VPN Client is not compatatible with Microsoft’s Internet Connection Sharing for Windows XP. Internet Connection Sharing must be uninstalled before the VPN Client can be installed”. I have had him ensure that the WXP firewall and any virus software is disabled. He is running this on a home network. ISPEC blocking is disabled. His Zone Alarm software is disabeled. I have been abled to load this client on 2 other WXP machines so far. Any suggestions? Thanks!

Joel