Please follow the following steps to run OneStep Accounting on Windows 7:

1. Installed both the OneStep Accounting and Interbase programs on Windows 7 as described in the readme.txt or the OneStep´s User Guide.
2. Goto Windows 7´s Control Panel and click on InterBase  Manager (32 bit) to start the Interbase Manager program. See screenshot.
3. While on the InterBase Manager´s window, uncheck Run the Interbase server as a service on Windows NT followed by clicking on the Start button to start the Interbase Server. See screenshot.
4. Run OneStep Accounting from the Start Menu.