The following are prerequisites
for developing SQL Server Mobile applications:
Windows 2000 SP4 or later, Windows XP SP1 or later, or Windows Server 2003.
Visual Studio 2005 in the development environment.
.NET Framework 2.0 in the server environment.
Microsoft ActiveSync 3.7.1 or later in the development and server environments. ActiveSync is available as a free download from Microsoft.
If you are using Windows XP SP2, you need to configure the Windows Firewall to allow HTTP access. Follow these steps:
Select Control Panel Windows Firewall.
Select the Advanced tab in the Windows Firewall dialog box.
Click the Settings button in the Network Connection Settings frame.
Check the Web Server (HTTP) checkbox.
Click the OK button on both dialog boxes to make the changes.