Thank you for your reply.
I had tried several of the suggested solutions previously but to no avail.
I resolved my issue by loading the program onto another computer which was able to download the updates and I then was able to complete my federal return and e-file it.
Prior to this issue, TurboTax had downloaded several updates with no issues. I still do not know why this last download refused to be completed....especially worrisome since it occurred 3 days before the tax submission deadline.
Thank you, again.