troubleshoot sql server timeout error messgae

I get following error message. How to fix it? It is sql server 2012

SQLState = 08001, NativeError = 258
Error = [Microsoft][SQL Server Native Client 10.0]Shared Memory Provider: Timeout error [258]. 
SQLState = 08001, NativeError = 258
Error = [Microsoft][SQL Server Native Client 10.0]Unable to complete login process due to delay in login response
SQLState = S1T00, NativeError = 0
Error = [Microsoft][SQL Server Native Client 10.0]Login timeout expired

SQLState = 08001, NativeError = 0
Error = [Microsoft][SQL Server Native Client 10.0]Unable to complete login process due to delay in opening server connection