HELP – Broken Website

Can anyone help me please?
Not sure what I’ve done but my website seems to have stopped working on IE9 🙁
It has all been working fine (I usually use Firefox on a Mac) but this morning as I was doing some work on it it started playing up a little, so I logged onto a Window’s PC and checked it in IE and its all messed up.
Here is an image of what it looks like on the Mac (and how it’s supposed to look)Mac
And here’s an image of what it looks like on IE this morning IE
Also, in IE I logged into the admin section and that was all messed up as well, here’s a screen grab of the plugins page plugins
I’ve tried deactivating all of the plugins but this didn’t fix the problems. I haven’t changed the theme at all recently so can’t see that it’s that.
Could anyone help me please, I feel like crying! :,(
Many, Many thanks
Jo