When working with Solidworks 2007 SP0 software you will need to set the language preference during the installation process; the program may run on any other default language. If you decide you want to change the language after installing the program, you can do so quite easily. You just need to go to C:\Program Files\SolidWorks\lang; once there you need to rename the English folder to the language of your choice (French, German etc.), and then rename that folder as English. Once done, just relaunch your "SolidWorks" software and the desired language should come up.
I'm using Solidworks 2007 SP0 and I want to set the language to French. Though I selected the option during the installation, the program is still in English.
Go to C:\Program Files\SolidWorks\lang,
Rename the English folder as "French" and the French folder as "English"