Below are guidelines for installing Open Server on the same server with other Sybase products:
On the Windows platform, installing Open Server 15.5 on the same server as Adaptive Server® 12.5.0.3 causes Adaptive Server to fail to start. Either upgrade Adaptive Server to 15.5, or follow the directions in the SDK and Open Server Installation Guide for Microsoft Windows.
Use .bat files to ensure that each product is started with the correct Open Server version and environment variables.
Sybase recommends that you do not mix versions of SDK and Open Server in the same directory. For example, do not install SDK 15.5 in a directory containing Open Server 12.5.1—in this case, upgrade both SDK and Open Server to 15.5.