https://blog.sqlauthority.com/2009/05/21/sql-server-fix-error-provider-named-pipes-provider-error-40-could-not-open-a-connection-to-sql-server-microsoft-sql-server-error/
排除以上情况后尝试如下
C:WindowsSystem32>sqlcmd -S PRC112dPBITRAINING -Y 20 -d AdventureWorksCo
HResult 0xFFFFFFFF, Level 16, State 1
SQL Server Network Interfaces: Error Locating Server/Instance Specified [xFFFFFFFF].
Sqlcmd: Error: Microsoft SQL Server Native Client 10.0 : A network-related or instance-specific erro
r has occurred while establishing a connection to SQL Server. Server is not found or not accessible.
Check if instance name is correct and if SQL Server is configured to allow remote connections. For
more information see SQL Server Books Online..
Sqlcmd: Error: Microsoft SQL Server Native Client 10.0 : Login timeout expired.
