Windows 8.1 & IE11

[Pheno]

All of a sudden whilst I was on the machine today the bottom taskbar has completely disappeared off the screen and the internet tab colours along the top have changed from the default blue to grey on a black background so now very difficult to see.

I have googled and searched on here but can't seem to find the answer to this combination of issues.  I was not doing anything unusual at the time - actually toggling between Ancestry and the GRO Index page.

I have not installed any updates today either.

Can anybody supply any instructions I can use to get the taskbar and the colour back please?

Thanks, Pheno