Good afternoon trt........I am at a complete loss to understand the reason for your being able to use your computer with IE but all efforts with Firefox are proving useless.
Please allow me to ask you a question before I give-up on the issue involved.... Obviously you have downloaded a Firefox 'set-up' file but have you run the file to install Firefox.? Initially you will have imported a file into your 'Downloads Folder' and that needs to be opened and 'run' for Firefox to actually be installed.
I am at a complete loss to understand your screen being split into half white and half blue. Computers are strange 'animals'.!!
Sorry, a further question.... Would you like to see if Google Chrome can be loaded as an alternative browser for you ?......I have Internet Explorer, Google Chrome, Firefox and Safari.
https://www.google.com/intl/en_uk/chrome/browser/?installdataindex=nosearch&hl=en-GB&brand=CHMA&utm_campaign=en-GB&utm_source=en-GB-ha-emea-uk-bk&utm_medium=ha