In some development scenarios it is necessary to include 64-bit SQL Server Compact 3.5 native DLLs in your project. For example, when you build an application that uses private deployment of SQL Server Compact 3.5 for a 64-bit target. If you are developing in a 64-bit environment, these DLLs are available in the %Program Files%\Microsoft SQL Server Compact Edition\v3.5 folder. However, the 64-bit SQL Server Compact 3.5 Runtime cannot be installed in a 32-bit Windows environment, so the 64-bit DLLs are not available in the default installation to the developer. Developers working in a 32-bit environment must download the 64-bit SQL Server Compact 3.5 Runtime Installer (SSCERuntime-ENU-x64.msi) and then extract its files. After extracting the files from the MSI, you can include the 64-bit native DLLs in a project by browsing to the directory into which they were extracted.
To extract SQL Server Compact 3.5 DLLs from the 64-bit SQL Server Compact Runtime Installer
Download the 64-bit SQL Server Compact 3.5 Runtime installer (SSCERuntime-ENU-x64.msi) from Microsoft SQL Server Compact 3.5 Web site.
Open a Command Prompt, and from the command line, create a directory in which to extract the files; for example, md c:\x64.
Change to the directory to which you downloaded the installer; for example, cd c:\InstallerDownloadDirectory.
On the command line, type msiexec /a SSCERuntime-ENU-x64.msi, and then press Enter.
When you are prompted for the network location, enter the full path to the directory you created in step 3; for example, c:\x64.If the directory you specify for the network location is c:\x64, the 64-bit native DLLs are extracted to the following location: c:\x64\Programs\Microsoft SQL Server Compact Edition\v3.5\Microsoft SQL Server Compact Edition\v3.5.