Maintenance for the week of October 6:
• [IN PROGRESS] ESO Store and Account System for maintenance – October 7, 6:00AM EDT (10:00 UTC) - 4:00PM EDT (20:00 UTC)
I cannot download ESO because my computer considers it malicious software.
It sounds like maybe a firewall/antivirus/security software deems ESO suspect. You can try looking at the settings for the software or trying different software for that purpose that isn't quite so over zealous.