Ive installed two programs since i upgraded an driver for my video card and java for the internet. Ive uninstalled and reinstalled firefox and that didnt do anything. I can however, use firefox in safe mode, which makes me think it was the java runtime enviroment.
With all of those issues, I would recommend to refresh Windows 8. Afterwards create a restore point before installing anything else in case it may be the cause, and you could just do a system restore to undo it.