Configuring computer to run another language besides the default language takes some effort to achieve. If you are only interested in French and German special characters, then there is no need to fiddle around with English or default languages settings of Windows on the computer. Franco-German Assistant is a handy application to insert French, German characters from standard English keyboard.
It shows a small toolbar at the top of the screen containing different special characters. You can click on any character to paste to the clipboard which can further added to the actual text document. Alternatively, you can use auto paste option to directly insert characters to documents from the toolbar itself.
It is a portable application and does not require installation. Just download [link], unzip and launch the application to see special character bar at the top of the screen. With auto paste option enabled, click on any special character to insert in any opened text document. Neat and useful!