Disable wireless network card Mac OS X I wonder if there is any way, how to turn off / disable the wireless network interface or driver, so I cannot connect to WiFi from running OS. I have MacBook Pro with OS X Mavericks.

The reason for this is I have some exams at the University and if I want to use my own notebook, I have to turn off the WiFi in some more permanent way (for example from BIOS, if I had PC).

I have installed rEFIt so I can enter to some kind of EFI Shell, but I honestly don't know, what I can do here to not destroy my computer.
You can move the IO80211Family.kext from /System/Library/Extensions. The Wi-Fi won't function without this file, so moving it will prevent the Wi-Fi from working. If you leave the file on an external drive, you won't be able to re-enable it without the file.

Alternatively, if you're able to disable the admin account, it's a bit easier. Go to System Preferences → Network → Wi-Fi → Advanced and require administrator authorisation to turn the Wi-Fi on.