If you cannot connect to a remote Microsoft SQL Server, one possible explanation is that your firewall, on either the ISP side or your Microsoft SQL Server machine, is blocking Port 1433, the default port used by Microsoft SQL Server. (Please note that you port 1433 is the default port; your Microsoft SQL Server may be configured to use a different port).
Please review these help links from Microsoft:
http://support.microsoft.com/default.aspx?scid=kb;en-us;287932
See these helpful links for tips on troubleshooting Microsoft SQL Server connectivity issues.
http://support.microsoft.com/default.aspx?scid=827422
http://www.databasejournal.com/features/mssql/article.php/3341651
No Anonymous Access (Recommended for Development Environment)
Allow Anonymous Access (Recommended for Production Environment)
Remote Database Access through a Firewall
Application Runs But No Data is Displayed