JJMack is right - but sometimes I noticed some problems when I've worked without Admin rights on not mine machine
Thanks so much for your replies.
I looked at previous threads regarding Windows updates and Admin rights.
But I couldn't see a way through this.
In the end Adobe support said that this issue requires a manual clean up of photoshop which involves uninstalling photoshop and then manually deleting Photoshop related system files folders and registries. And then reinstalling of course.
The issue is now resolved! (Droplet works, and is lightning quick!!)