I have a WLAN USB adapter it's a realtek and it came with a setup cd but my netbook doesn't have a cd drive, is their any way to set it up on another computer then transfer it to this one by flash drive or something? Or do I have to download something please help, thanks

If you are installing it on a desk top the wireless in your lap top should pick it up from that location

Every netbook I've seen has WiFi built in. Why would you need an external adapter?