If you've ever tried to insert a signature in Outlook, you've probably noticed that it doesn't work properly. That's because the image that you want to use for your signature isn't available in Outlook. The best solution is to go to the Microsoft Office Desktop Apps and open them as administrator. Once this is done, you can then install the Microsoft Office Outlook software, and then click the 'Signatures' button to get the signature window back. This is the way you can change outlook email signature by yourself.