A couple years ago I bought Flash Professional CS6 from the adobe website and downloaded the mac version. At that time, my apple laptop was my most powerful computer. Now I have a more powerful pc with windows 10.
Can I download Flash Professional CS6 for PC?
I believe so. At least, I did do that with a CC version. You're licensed to use Flash Pro on two machines, if you're already using it on two Macs, make sure to deauthorize one of them before trying the PC version.
In my case I wanted to try Flash Pro under Windows 10, to check into some issues that had been reported. I did the install to then be greeted with a message about already being signed in on two other machines. That was a surprise, I thought I was only signed in on one, maybe someone else was using my login! You're given an option to sign out of all other machines, which is what I did (it may not work that way with CS6). Then I was able to use the Windows version. When I went back to the Mac version I had to sign back in again.
The funny thing in my case is that I'm running Windows 10 on my MacBook Pro, that is also where I'm running the Mac version. So, my two machine allowance is taken up on one physical machine!