I too had this problem this morning, exact error, restarted the download 6 times from 0/1035.90MB, finally after I set the ffxivboot to Run as administrator and run this program in compatibility mode for windows xp service pack 3, then double checked that the admin permission were all checked under the security tab.

after those steps It was all good, from start to finish the whole 1035.90 MB just 2 mins ago. not sure if this is a fix or I just got lucky
and my connection is a slow wireless ISP in the middle of nowhere in TX
which is only 120kb/s
no anti virus or anything like that installed on this PC