You will need to install the Dutch keyboard on your computer, and then you will be able to type the accent followed by the letter, which will make the letter appear with the accent. For example, to type "ë", you will first need to type " and then e. To install the Dutch keyboard you will need to go to your Control Panel in Windows and go to "Language", where you will be able to add keyboards for lots of different languages. If you can't figure it out, I would recommend googling for "Dutch keyboard" with the version of Windows you are running and you should be able to find lots of information on how exactly to do it on your version of Windows.