64-bit capable applications normally run in 64-bit mode on Macs with a 64-bit processor and Mac OS X 10.6 or later, but there may be occasions - if they depend on 32-bit plug-ins or drivers for example - when you may need to open them in 32-bit mode.
On Mac OS X 10.6 or later, Application Wizard lets you easily force 64-bit capable applications to run in 32-bit mode, either always or just once.
Open the Application Wizard pane in System Preferences and click Applications.
Click the Add (+) button at the bottom of the list, browse and select the application, and click Add.
Select the "Open in 32-bit mode" option. When launched from the Open menu the application will always run in 32-bit mode.
Select the application in the Open menu.
Press the Control key: if the application can open in 32-bit mode, its icon will switch to the 32-bit badge and Application Wizard will open it in 32-bit mode.