You might not even need to use the disc at all. On the disc will be the drivers for the network adapter, but windows may already have them built in.
It's worth plugging the adapter in and seeing whether Windows automatically detects and installs drivers for it. Windows is surprisingly good at this nowadays. If it does, you can then browse to the manufacturer's website and download the latest drivers over the Internet, or just leave the windows ones if you want!
If that doesn't work then another option would be to plug your PC directly in to your WiFi router using a network cable. Then you should be able to browse to the manufacturer's website and get the right drivers for your wireless adapter.