The other day,when I run my asp.net 2.0 web application, an anoy exception always be thrown stated that "under default setting sqlserver2005 doesn't allow remote connection, Named pipe 40 error". But actually I was connecting to sqlserver 2000.

after a lot of searching, I resolved this problem by updating sqlserver2000 to sp3.

The connetion string i was using is "server=ip;database=dbname;user id=username;password=pwd"