If you install a USB wireless card, you may want to disable the internal card. The easiest way is by using the BIOS, but that often disables all networking device. This is the case particularly on Lenovo laptops. Turning the hardware wireless switch to the off position does the same thing. Follow these steps to add the internal wireless module to the blacklist:

  1. Open Terminal
  2. Type lspci -nnk | grep -iA2 net and hit Enter
  3. Make note of the wireless module (found in brackets after the make/model of the adapter)
  4. In Terminal, type sudo gedit /etc/modprobe.d/blacklist.conf and confirm your root password
  5. Add a comment and module exclusion and click File - Save

Below is an example from a Lenovo laptop:

#Intel Wireless 3945ABG
blacklist iwl3945