In client properties, run compatibility mode for Windows 98 / Me. Then you might need to execute the client a couple time but you should be able to play on Windows 8
It shouldn't be a problem, you will still have to use the compatibility mode. There was a user who said it worked, I have not tried it myself.
Win10 is coming out in a day, at least the released version. I've been on different forums where people who signed up for beta and tried it, said that it's almost identical as Win7, with small fixes and upgrades as well as some tools from Win8/8.1. I'm worried about the application tool though, as I've not heard a lot about that feature from the beta testers. I'll be glad if it's possible to disable it!