How many wifi internet adapters can be installed at the same time on one computer? Will the installations interfere with eachother?

I had a "Wireless G card" of Linksys a few years ago and I used it on a laptop (someone else installed it). I never uninstalled it. Then several months ago, I bought and installed a Belkin usb-connectable type N adapter on the same computer, and it has been working very well. I just wonder if we could also try another brand and model of wireless adapter, and then be able to use either at any time, like in case one day, one of them stops working or goes bad.

I really do not remember all of the choices I made when I firt installed the Belkin adapter, so I have no idea if the computer itself needed to be configured as to use one and only one wireless adapter.