Everything's been going swimmingly since the end of March, when I basically turned my back on Internet Explorer and started using Firefox instead. No problems at all with Firefox, but then all of a sudden, as of yesterday, I can't get Firefox to work at all!
When I try, I immediately get this...

...which then turns into this...

And I'm not sure if it has anything to do with it, but there's some sort of "Windows Update" thing that my machine keeps trying to install, but it only gets so far and then the installation fails, and I don't know what the heck that's all about. Here's a pic...

As usual, any help will be very much appreciated.
Cheers
Ben