No no I'm good...
Damn how many is there?
There might be a few systems I forgot to mention, but there is more Windows systems than you think.
I don't know if I could call a Windows codename (ex. Windows Chicago, the codename for Windows 95 in its alpha/beta stage) an actual Windows system.
If I were to read off the known (leaked) builds of beta builds you would be wasting about 2 hours reading all of them, probably because a very large majority where Windows Memphis (98) leaks.