http://www.drivehq.com/help/features/PricingPlans.aspx and click on the link to this page:
You can get up to 1GB storage and download bytes. Please note DriveHQ free service is designed for personal and casual use only. Generally, we offer free 1GB, but it doesn't mean we expect users to upload 1GB files or download 1GB files in one day. An 800GB file is a very very huge file, and it is not considered casual use at all. Please consider upgrading your account to a paid account. Or you can feel free to check if there is any other reliable service to transfer 800GB file free of charge. Thank you for your understandings.