Ok, so saved to desktop and finally written to disk. Booted from disk through F8 and a new blue screen comes up...
Recovery
Your PC needs to be repaired
A required device isn't connected or can't be accessed.
Error code: oxcoooooof
You'll need to use the recovery tools on your installation media. If you don't have any installation media (like a disc or USB device), contact your administrator or PC manufacturer
Press Enter to try again (I did - nowt)
Press F8 for Startup Settings (did this too - again, nowt)
Oh dear. If this is the end of the line as far as your help can go Essexboy, then I just want to thank you very much indeed for all your time and helpfulness. This doesn't look very good...