PuTTY connection refused on Windows 8.1

I installed PuTTY over a year ago on Windows 7 and frequently use it to access my droplet running Ubuntu 14.04. We are preparing to ship our belongings, and I will be staying behind to complete my work contract for a few more months. So I purchased a Windows 8.1 laptop to use in the interim. All of the tools that I need are set up on it, except that I have been banging my head against the wall for a few days now trying to get PuTTY to connect to my droplet. It appears to be installed correctly, but no matter what I do, I get a connection refused error. My poor husband is having to do all of the packing amidst all of my head-banging, and I sense that his fuse is growing short, so I thought I would ask for help.

Here are some of the things I’ve tried:

• First installed PuTTY Release 0.63, then installed Release 0.64 (currently installed)
• Made sure all settings on the Windows 8 setup match those on the Windows 7 machine
• Generated new SSH keys and specified the Private key file for authentication under SSH Auth in PuTTY (Full disclosure: the whole SSH key stuff is somewhat fuzzy to me, but I’m leary of doing anything that might mess up the authentication that is working on my desktop since that is my only lifeline to my droplet right now.)
• Telling Windows to allow PuTTY to pass through the firewall
• Lots of research that turned up people saying PuTTY works just fine on Windows 8. (Note: my laptop uses an AMD processor, not Intel. Could that make a difference?)

Thank you for any pointers you can offer.

Bonnie