Method 1: Restore Windows Update Repository
Download and run Reimage Plus to scan and restore corrupt and missing repositories from http://www.reimageplus.com/includes/router_land.php?tracking=RNWassabi&lpx=drp&banner=WW&adgroup=W_UpdatedError_0x80070057
For Method 2/3/4/5 (visit): https://appuals.com/windows-update-error-0x80070057/