You should not have the Skype Translator client and the Skype for modern Windows client installed at the same time but you can have Skype for Windows Desktop installed on the same computer on which you are planning to install Skype Translator.

To get the most out of Skype Translator and avoid any confusion, make sure that you are only signed in to Skype Translator when making a call. Ideally, you should be logged out of all other clients.