I have been using PS and LR on two computers for a long time. Then I bought as third computer and installed both progs on the new computer, deleting from the older computer. But now it seems I can only use PS and LR on the new one. i.e. only on one computer, even though I have disinstalled on the old one. Any clues please?
Which versions are installed? Older software needs to be deactivated before uninstalling. Creative Cloud software can be activated & deactivated through your Adobe account.
99jon is correct. You will need to go into your account details by logging in through a browser or or by chatting / calling Adobe support. Once logged in go to Manage Plan > Right Hand Column second tile shows your Activated Devices > there you will need to deactivate the older computer. You can only have two computers active with the same account.