I recently cloned my Windows 7 root drive and after having done that, my properly licensed CS3 version of Photoshop no longer runs because, when I launch it, I get the ‘Software Setup’ window. Adobe refuses to provide the necessary information and I have less than no interest in changing versions of Photoshop or my OS.
Try accepting that you WILL need to update both system and Photoshop if you want to use it again. The activation servers for CS3 were turned off years ago (I don't say this is a good thing); there is no prospect of getting it working again now you've broken the licensing. And the current subscription product is not for Windows 7.
The only thing that would work now would be the activation-free installer and matching key that Adobe briefly provided to licensed users when they first switched off the activation servers. Unfortunately, there is no conventional route for obtaining these today - the customer service operators won't help. Perhaps a formal written complaint to Adobe, questioning the legality of witholding the software you paid for and mentioning your problem could be resolved by providing the activation-free installers they have already created, would be worth trying.