When saving a web page using Internet Explorer, I prefer to save it in .mht format rather than a .html file with a folder containing all the files for the page (when you need to save a lot of files, those folders are really annoying). Sadly standard Mozilla Firefox cannot open those .mht file .. but luckily there’s a Mozilla add-ons that allows us to read .mht file: UnMHT.
Just go to the website and install the add-ons. If you want to download the add-ons and then install it on another computer, go to the homepage of the project. Download the “.xpi” file and then drag the file to your Firefox.