I bought the Elder Scrolls Anthology and one of the ideas was to get the missing Skyrim add-ons with the same price.

I just tried installing Dragonborn and Hearthfire, but there is no option for it. I can either remove Skyrim or reinstall.

I tried reinstalling, but after a validation i only get an error message saying "1 files failed to validate and will be reacquired".

In that window i can only click "Ok" and after that nothing happens.

I mean this installation program can't be so stupid...

Are there any solutions to this issue? No way to just install the add-ons?

Or do i really have to remove Skyrim in order to get the addons installed?

If i do that, is it enough to take a back-up of the game saves and Skyrim.ini and Skyrimprefs.ini to be able to continue my game?

Please don't say that i have to buy Drabonborn again to be able to install it...

Just start the game, so the Luncher appears. Then click Data Files and check if all addons are there.

I'm using the SSKE, i only get the launcher if i run it.

But, no, the add-ons are not there, only Dawnguard, which i bought earlier.

As i said, the installation doesn't actually start at all.

Or is the SSKE now the reason why i cannot reinstall?

Have you actually registered the cd-key from Anthology on Steam? You'll need to do that. Even if you have the disc, the DLCs won't install without them being tied to your account.

No, i haven't. How do i register it?

I use non-English language in my Steam, but it should look like this:

-In the lower-right corner, there's "Add game" button. Click it and select "Activate Steam product", and type the cd-key in a popup that should appear.

I'm unsure how to install just one DLC, as Steam will probably try to immediately download all new content. If you have a reliable and quite fast internet connection, it shouldn't take too long.

Yep, thanks for putting me in the correct path, so to say.

I finally found that myself also. After registering Steam installed the Skyrim Legendary Editon and now i have all the add-ons.