I see nowhere on my account or subscription page where I can deactivate current computer and add to new one. I have almost 3 years left on my subscription.. Thanks for your time and assistance.
Hi @TrueBeachLover, yes, you can move your subscription to a new computer, no need to buy a new one 
What you can do depends on which version of Avast Account you have:
If you already have the new Avast Account, you can manually deactivate the old device and free up the seat there. You’ll find the steps in the section “How can I manage the devices using my subscription?” in this article: https://support.avast.com/en-ww/article/avast-account-faqs-new
If you’re still on the older version of Avast Account (which is likely, as the new version isn’t rolled out to everyone yet), manual deactivation isn’t available. In that case, just uninstall Avast from the old computer and install it on the new one. The old device seat should be freed automatically shortly after uninstalling. This process is described here: How to transfer an Avast subscription to another device | Avast