Today was about the 3rd or 4th time in the last few months that I boot up the PC and find that the Firefox exe has disappeared. So frustrating. Yes I can and do re-install, but it's 30-45 mins each time. Does anyone know what might be causing this. I am very careful with downloads and use only licensed software. Could it be the VIPRE anti-virus/firewall? Running on Windows 10 - everything is up to date and usually very stable.