How do I associate an e-mail program with Office Writer? The help screens don't seem to cover this topic.

I am using Libreoffice Writer Version: (x64)
I want to send a document as an an e-mail, and I’m told there is no e-mail program installed. It says “Please install one, or create an association in default programs control panel if one already exists” But I cannot find anything to tell me how to do it. It covers Sending Documents as E-mail, but doesn’t tell you what to do if there is no e-mail program associated with it…

First do you have a dedicated email client installed on your computer?
It would help if you were to specify what operating system are using.
If you check the Tools/Options menus entry in LO, there should be an entry in the dialog that opens on the left at the bottom that says internet. click the > to expand the list further and select Internet. It was filled in on my system with Thunderbird as that is my default email client. It didn’t work as Thunderbird was capitalized. Once I made the T lower case, it worked.

Thanks for your help sir. I am using windows 10 and I only use Google’s Gmail

Then you have to install an email program, set up it to work with your Gmail account and set up the association in LibreOffice as described by AdmFubar.