fail2ban for windows 2008 RDP [duplicate]
For Windows, The most straightforward option out there (from the ones that I tested) is a commercial solution called RdpGuard.
There's also one solution called IPBan, although I never tried that one.
You can also secure RDP requiring client certificates, check this article.
More interesting articles about securing RDP against brute force attacks:
Automatically block RDP attacks on your Windows Server 2008
Automatically banning IPs with Windows Firewall after scanning the eventlog