Installing Photoshop after re installing windows

Recently had to re install windows 10, so couldn't deactivate Photoshop. Have installed Photoshop back to main pc, but when I try and install a "second copy" to my lap top it keeps suggesting install "trial"-now I realise that it probably thinks I am already using the second install,but surely adobe must have a way around this when people have to reinstall there operating system--I am a bit wary of this as I don't want adobe to start billing me for two Creative cloud accounts

Adobe appear to be very difficult to email about this and I cannot find an email address for this sort of problem

any help gratefully received.