EDIT: Make sure Win2DS is running on your computer before you start Ds2win on your DS
I use acekard 2i.
Start up DS2WIN and select auto connect.
When it asks for IP you type in your computers IP. Find it by pressing Windowsbutton + R and type CMD. A commandline(i think thats what its called) comes up and then type IPCONFIG. And you should be able to find your IP there.
Then it prompts you for password. If you didnt enter one just press start. And there we go. You should be connected