"Abandoware" does not exist in the law, at least in U.S or in France ( I don't know for other countries who each have their own local laws ).
Abandonware is more, less or not at all tolerated, ignored for old games that are not sold anymore because the rights owner does not really care about them financially. Still it's illegal.
The only "originally copyrighted" game that you can download must be around 70 years old ( the duration varies depending of the country ), when then it falls into the public domain.
As for Daggerfall, until Zenimax/Bethesda states that it can be downloaded for free. It's illegal, and debating about it is prohibited here