Hmmm...I've been using Windows and Internet Explorer to log in, and have had no problem whatsoever. I haven't a clue what any of those other things (Firefox, et al.) are - no do I care - but to date I've had no problem with this eight-year-old set-up.
(Life being what it is, I'll probably wish I hadn't said that.)

If your security setting is less than "maximum" it will work without problems.
Internet Explorer is the web browser embedded with Windows, and generally functional if a bit backwards. The browser is what takes the HTML script (HTML being a rudimentary type of computer program) and interprets it to make the web pages you see. The script looks like this:
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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "
http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="
http://www.w3.org/1999/xhtml"><head>
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<script type="text/javascript">!window.jQuery && document.write(unescape('%3Cscript
etc (this is the first bit of the source HTML for this page).
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When you visit a web page, what you actually do is download this script (which is relatively small by download standards) and the browser interprets the script on your local machine to construct the web page you see.
Firefox, Chrome and Opera are other brands of web browser (all free) that are intended to do the same thing. There are standards for how the scripts are to be interpreted, but they are not strenuously enforced by either the web page makers or the browser makers. Internet Explorer is pretty notorious for making up their own "standards", ostensibly to "enhance the experience" but many times had the effect, intentional or not, to make web pages ONLY work on Internet explorer and not the others.
In many cases this has led to visceral hatred of Internet Explorer/Microsoft because you many times have to make regular script for most people, and a hacked-up script to work with IE. This has generally gotten better as later versions have been produced, since said visceral hatred has led to drastic loss of market share for IE and they have been forced to get their act together and stop playing games. IE 6 is the most evil, the later versions are progressively less evil.
Right now, depending on whose numbers you look at, Chrome (from Google) is at about 40%, IE (all versions) is 30%, Firefox (from mozilla.org) is about 20%, and Safari (Macintosh default browser) is about 8%. All are free. Chrome generally runs MUCH MUCH faster than the others on Windows.
Brett