Hey, is there a way to set up a Wi-Fi hotspot using my Laptop which is connected to WiFi?
Also, it must be with WEP security so that my DS can connect.
Also, it must be with WEP security so that my DS can connect.


It is, through the network setup panelYou can do this on *nix/BSD with a compatible wireless adapter - wouldn't have a clue if it's possible to set this up on Windows though.
It is, through the network setup panel

Wait, sorry, I thought you meant hosting from a secondary card, I didn't even know it was possible to host a network from the same card you were recieving a connection fromThen you might want to inform Jackus how.
Edit :
A cursory googling about hosting on the same adapter as a client for Windows seems to provide some stories about a software solution called 'Connectify' - but from what I understand that utilizes the built-in hosted network feature, so sadly it's probably WPA2 only.
