The SQL Anywhere .NET Data Provider DLL (install-dir\Assembly\v2\iAnywhere.Data.SQLAnywhere.dll) needs to be registered in the Global Assembly Cache on Windows (except Windows CE). The Global Assembly Cache lists all the registered programs on your machine. When you install the .NET Data Provider, the .NET Data Provider installation program registers it. On Windows CE, you do not need to register the DLL.
If you are deploying the .NET Data Provider, you must register the .NET Data Provider DLL (install-dir\Assembly\v2\iAnywhere.Data.SQLAnywhere.dll) using the gacutil utility that is included with the .NET Framework.