I'm still lumbering along with XP. I know I should breakdown and buy another computer, but I'm just tired of the fight to keep the OS running and them having to get a whole new computer. As I understand it, the OS is considered a service, not an actual thing that is supposed to work.
Anyway, there is a script on MEF that will choke my CPU if it's on the page I'm looking at. I can see on Windows Task Manager that it uses 100% of CPU time.
Edit: I'm using Firefox 52.8.0