Windows XP operating system with Firefox and Internet Explorer depending what I want to do. I have found some things I want to do don't run on Firefox.
Chrome seems to insinuate itself onto my computer without me asking for it, as do a number of other browsers. They come with other program downloads if you are not careful and take over as your default browser, which is a pain in the but. Then I waste time going into programs on control panel to delete them.
Tegan. Tell him to sort it back again for you. 
My DS once helped me remove a virus which was about a bogus security program and literally locking up my computer.
I told him what the problem was, he Googled the solution then talked me though on the phone step by many steps on how to get rid of it completely from all the bits of computer where it was hiding.
They have their uses, these computer bods.