How do I change my PC from 40 or 104 bits to 64 or 128 bits?

When trying to Connect my computer to my wireless net work, I get the message ';the network key should be 40 bits or 104 bits depending on your network configuration';. According to D-Link support, my router and adapter are fine. They said all I have to do is change my PC from 40 or 104 bits to 64 or 128 bits. Does anyone know how to do this? (I already tried HP support- they sent me here)How do I change my PC from 40 or 104 bits to 64 or 128 bits?
You want to switch to 128 bit encryption. HP sent you to Yahoo Answers? That's just silly.

You don't include your O/S which would be helpful. You have to set the encryption in your wireless network connection. You should either see it in the system tray or the Control Panel.