I managed, somehow, by a fluke or miracle to figure out a totally bizarre way to let the BIOS reinstall. There's something loose in the hardware, as I can get the laptop on, but as soon as I move it the screen glitches out with a screech and that's it. Maybe it was the tension in my hand but I noticed that I got further if I squeezed the right corner of the casing, this let the BIOS setup complete and then got me in, so using a mouse with left hand while squeezing with right hand, I managed to keep it on long enough to copy my stuff. I'll still be £350 down but at least it's pay in 6 months so I won't worry about it till then. I literally restarted that machine for 5 hours, trying leaving it, trying Windows V, Windows B, both of them together, over and over. Sometimes it would come on and then just die again, eventually - progress. Today was the closest I have ever been to CTB and it's still not over, there's still more to deal with and I literally can't pay people to give me the right advice, but I will try to leave that until tomorrow now.