It appears this is a Windows 8 fault and the only way to recover is to use the Recovery Disc.
I then discover that I was supposed to make this Recovery Disc myself when I first got the PC

I have two options, Go to Pissy World or other computer repair shop and let them wipe the machine clean to factory settings for £50
or buy a windows 8 recovery disc off amazon for £10 in the vain hope that it works

In the meantime ive been drinking.....heavily

So a timely reminder to anyone not yet made a Recovery/Back up Disc, do it now
Geoff