abredt said:
What do you mean by use IE alongside Firefox?
Browsers are pretty much like other applications---you can use more than one browser to do similar things, just as you might use either Photoshop or Paint to manipulate photos. They can co-exist. Open whichever you like. I use Pale Moon as my default browser, but must use Chrome at times, particularly for Sling TV. Sling made a change maybe a year ago and you are now forced to use Chrome to watch Sling TV on a PC monitor.

One thing you would have to consider is transferring bookmarks/favorites from one browser to another. Browsers typically have export and import facilities to manage that.