Can't access pc after changing to windows 10. Can't get anything except a blue screen and constantly recycling 'inaccessible boot device' and we'll restart for you. Took several hours downloading osl (or whatever) on my laptop and; put it on usb and tried that in my desktop but that was no good either. Also tried original windows 7 disc and a boot disc that I bought and also the backup discs none of which have any affect. I can't afford a new pc on my pension and I can't afford to take it to a mechanic. Any clues anybody?