I don't want to download another browser at work so that they don't think I'm using their internet for my own entertainment (which I do all the time
). Then again, sooner or later I should consider doing it though. Even the websites I need to use for work take ages to load or don't load at all. I can always say that it was necessary to update the browser in order to finish my projects in time. 
I have Firefox and Chrome on my laptop but I don't really use the latter. At work I'm dealing with an ancient IE. 
You can always download for work purpose too, no? Or you can maybe upgrade IE? I believe their latest version is IE 11.
You can find out by going to Help (top of the browser once you open it) and then clicking on 'About Internet Explorer'. That should tell you which version you are using. I don't think many these days use this browser anyway so should be justified to download another that works better - be it Chrome or Firefox.
Also, you are network connection might be slow or the computer you are on might be a bit old too.