Error 1005 usually occurs if the launcher does not have the required permissions to access certain folders. The first thing you'll want to try is running the launcher as an administrator.

Here is how to automatically run the launcher as administrator:

1. Right-click on the launcher icon.
2. Click on Properties.
3. In the Shortcut tab, click on the Advanced button.
4. Tick the Run as an administrator box, and then click on OK. This option may be available under the Compatibility tab of some versions of Windows.

To do this, on your desktop, right click the launcher and choose "Run as Administrator."

You should also check your anti-virus and firewall exceptions as well. The following locations need exceptions.

Bethesda.net_launcher: C:\Program Files (x86)\ZenimaxOnline\Launcher
ESO.exe: C:\Program Files (x86)\ZenimaxOnline\The Elder Scrolls Online\game\client\eso.exe
Steam.exe: C:\Program Files (x86)\Steam\steam.exe