Bingo! I ran AVG and Malwarebytes, both found a heap of stuff that windows hadn’t seen. And as with Mark, unreal seems to be booting exactly as it should now. I still need to download all my plugins to open my actual projects, but I’m pretty certain that malware was issue too.
Thanks for all your help Sean, I know I have taken up a considerable amount of your time, It was much appreciated though. Sorry that I missed such an easy fix, I should have thought to check with another scanner to begin with.
And thanks again Mark!
I look forward to getting back to my projects now though! 