SOLVED! How to grant 'Allow log on through Terminal Services Right'

1. Run gpedit.msc (local group policy editor)
2. Expand Local Computer Policy –> Computer Configuration –> Windows Settings –> Security Settings –> Local Policies –> User Rights Management
3. Look for the setting called Allow log on through Remote Desktop Services
4. Double click this policy to open it.
5. Add the user/group you would like to have remote access to the box.

That's it, now you can login remotely.