Mass Effect 3 Won't Install

[jonathanwylie]

I bought Mass Effect 3 from Amazon, and downloaded the 10GB of data files required for the install, (over several days I may add due to the speed of my internet). When I install through Origin, it gets to 98% and stops. The error message is that the disc is dirty or may need cleaned,  please try again or download again from your library. It is obviously not a dirty disc as it was a download, so how can i fix  this? I really don't want to spend several more days downloading Mass Effect 3 again if the same thing may happen again?! Help?