To install your Email Signature in Outlook for Windows, please follow the steps below:
Make sure to use Chrome Browser (Safari or Firefox will mess up the formatting)
Click on the 'Copy Signature' button to copy your signature.
In Outlook, go to File > Options > Mail > Signatures.
Click on the 'New' button to create a new signature and enter a name for your signature.
Click in the Signature text box and delete any existing text and Paste (ctrl+v) your signature.
Under 'Choose Default Signature' please ensure both the 'New Messages' and 'Replies/Forwards' are set to your newly created signature.
And voila! Your Email Signature will be right in place.