I've answered you on December 18, then January 22, the last email I've sent on January 29 from another mailbox (I guessed that the previous one hasn't reached you).
Regarding the problem itself. I would advice downloading from another place with fast internet and trying to install there. It may be at work, neighbour, relative and so on. Save files to flash or burn disk and only after this, try to install from there. So you will surely know the distributive is intact.
If problem repeats on your home computer then, most likely, one of your memory modules mulfunctions.