It doesn't make any difference what the server's service accounts are. As long as you're connecting with an account (windows or sql) that has login rights on the other server.
Windows firewall stopped doesn't mean there's no firewall. There may be a hardware firewall on the network.
Can you ping the other server from the one you're working on?
Is the SQL Service started on that other server?
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability