I bought Photoshop CS5 for my MacBook a while ago and it recently stopped working. I tried to reinstall it from my account onto my windows PC but I only have the option to download .dmg files in various languages and not the windows .exe file. Anyone know how I can download CS5 for my Windows PC?
There is no way of doing that any more, I'm afraid.
Back in the Creative Suite days, purchases were platform specific: Windows only or Mac only. Adobe did offer crossgrades from Windows to Mac and vice versa but that stopped many years ago. Even then, crossgrades still involved a paid-for upgrade e.g. CS5 Windows to CS6 Mac.
Have you considered subscribing to a Cloud plan and running modern software on your Windows device? One advantage of Cloud apps is that the operating system no longer matters; you can run them on Mac or Windows.
you can download and install a windows version, but you can't activate it, because the mac and win programs would have different serial numbers (as mentioned by @Barbara Ash). with the win version, you would be installing a 30 day trial version.