I would love to know, If there is a way to mitigate DDos/Dos attacks on Windows. In Linux we can Mitigate using the almighty
iptables, but I wonder if there an equivalent for Windows.
Considering you already know IPTables, which is software mitigation, you could do the same thing in Windows by simply scanning the DNS requests and block IPs in the firewall.
It's important to understand that this won't help if your hardware fails under the load. You might get a better answer at ServerFault.