Before installing a second language pair, please make sure you have closed your Office applications and also the SYSTRAN 8 Translator applications.
To make sure that you have closed all your applications:
1. Open the Task Manager
2. Check for any item with SYSTRAN (systranserviceintegrator, SYSTRAN.TrayIcon, etc). End these tasks.
3. Check for any item with WORD, EXCEL, POWERPOINT, OUTLOOK. End these tasks.
Then follow the instructions described here.