HI people. I had SQL Server 2005 on Windows XP 32bit and just used this connection string Server=.\SQLEXPRESS;database=GroupALD; Integrated Security=True" Now I have Windows 7 64bit and SQL Server 2008 R2 I'm trying to connect database with same string but its shows this error Cannot open database "GroupALD" requested by the login. The login failed. Login failed for user 'lester\les'. Can somebody help me? I'm using C# and Winforms