i have this problem for 2 days and i couldn't solve it
when try to add new connection to visual studio get error " Can't open because it is version 661 this server support version 655 and earlier . A downgrade is no supported "
i making in my visual studio default sql server instant name is empty
i have Visual studio ultimate 2010 and SQL server 10.0.1600.22RTMExpress Edition
what should i do ?