In my last Win 7 computer, I could go to the envelope printing page in Word, click the "insert address" icon, and I would get a window that said "Outlook", from which I could go to any of my Outlook contact lists and select an address to print.
I have installed the same two programs (MS Word 2010 and MS Outlook 2010) on my new Win 10 computer. All the Outlook files are on the new computer, and all the contacts display correctly in Outlook. Both programs work fine, except that when I click the "insert address" icon in Word Envelope, It takes me directly to an empty address book, with no option to go to Outlook. See attached snips.