Try Windows 7
Windows 7 beta is ready to test drive now.
https://www.microsoft.com/windows/windows-7/beta-download.aspx
I have installed it on two of my computers. So far, I feel good about it. And I am trying to install it on my home computer.
If you want to use TTS, the TTS voice inside the beta version is the "Microsoft Anna". You can have a try with it as well.