I noticed a post about picasa being updated to connect with google photos, so I checked and there was an uipdate, which I duly downloaded and installed. It appeared to work, well the big green button was changed from share on google+ (to share on google photos). There is a However..
Now each time I restart picasa I get a request to update and the green button is back to connecting with google+. Looking at the on-line forums and blogs indicates that similar continual update message have plagued some user for a couple of years and there seems no clean re-install options other than deleting picasa altogether. I’d rather find a simpler solution so I’ll keep looking.