mddx141: What, exactly is the top upgrade? Do you mean the light fixture? If so, I don't think that's the solution. If that was the case, Pingy would not say, "Be sure to back up your save!!!". He would say instead, "Be sure to buy a light for your house!!!".
TurkeyPie: When your computer deletes tracking cookies, it also deletes your save. The game says to "back up your save", but I do not know how to do so. Sorry for the lack of a solution; I would like to know, too.