从Virtual PC连接到SQL Server

I have VS 2008 and SQL Server 2005 Developer edition installed on my desktop. I have a instance of XP running in Virtual PC and want to connect to the dev instance. I am logged on as a domain user on both the desktop and the Virtual instance of XP. When I try to connect I get a message saying "Server does not exist or access denied". What do I need to do to connect. I am using trusted connection and the userid has privileges on the DB.I have VS 2008 and SQL Server 2005 Developer ed