Trying to remove my 1st PC for new PS6 install. Last cd version sold.

To clarify terms, are you really using PS6 or do you actually mean Photoshop CS6?  There's literally a decade of difference between the two products. I can't confirm or deny if PS6 is still viable. Most likely, not. 

Did you deactivate Creative Suite from your previously installed devices first?
That's critically important because your individual license has a strict activation limit. Remote deactivation of Creative Suite is not possible.
- https://helpx.adobe.com/download-install/kb/activate-deactivate-products.html
- https://helpx.adobe.com/download-install/kb/activation-deactivation-help.html

If the old devices are dead or no longer in your possession, you're stuck. You won't be allowed to activate CS on another device.
MODERN OPTIONS:
==============
Photoshop Elements (3 year license, no subscription needed).
https://www.adobe.com/products/photoshop-elements.html

Creative Cloud Photography (Annual & Monthly plan options). 
https://www.adobe.com/creativecloud/photography.html

Creative Cloud Bundles & Single App Plans for mobile, web & desktops
https://www.adobe.com/creativecloud/plans.html

Adobe changed their "resetting activations" policy June of last year.
They no longer reset activations.
The "no products" actually referes to Adobe creative cloud products.
Unless you can do it yourself from your Adobe account, you're out of luck.

BOTTOM LINE:  You are 99.999999999% out  of luck.  You can forget about using PS6.

What you need to do is deactivate one of the previous installs. You do that under the menu Help > Deactivate.

If you can no longer access the previous installs, there's nothing you can do. Adobe will not extend the number of activations beyond the allowed two. The only way is to deactivate first.