Just to explain this in detail:

Once you have downloaded the content you want and you have the tick saying it's ready to install, click the "Downloadable content" line on the laucher again, click the item you have downloaded and in the bottom right of the screen it will say "Install", click this and you should be good to go. Note that it appears that you need to enter something into the preorder code redemption box, but ignore this and just click install (at least for the GOG version, not sure about others.

You don't understand him. He reinstalled the game and he has no Troll Trouble in Additional Content at all. I got the exact same problem. Reinstalled the game, logged to my old account and no Troll DLC available. Deleted it from Downloads folder, the same. Also, I think it didn't installed properly the 1st time either, as I had the same info in game: join witcher site, get dlc bla bla bla on poster in front of tavern. It's messed up :/

Yes, this is the exact problem.

Edit: Was just sent the code for the magical suit from my retailer and that code is rejected as invalid too, so I guess this is all just a database screwup.

Maybe you got the code wrong?

That caused me some trouble yesterday.
I mistook an "I" for a "T", and an "o" (oh) for a "0" (zero).

Sadly this is not the case. Even if it were, it doesn't explain why previously available DLC has vanished.

I've done this, and neither troll trouble nor my collecters edition dlc show up in game, despite having a green check box next to both.

The same goes for me. I have a green check at both dlc's and the files are there, and I can see the troll quest on the notice board in Flotsam, but when I take the quest, it doesn't show up on my To Do list. :-(

Yesterday I must have hit the time window when DLCs were installing fine from the server: the Troll, Swordsman Suit and Roche Jacket show a tick mark.

Then I started the download of the English voice-oners and captions. In both cases the downloader acs fully: after the download is done and verified, it starts anew in a loop. This sertainly is nt by design. Anyone having the same problem?

Have you tried running the patcher.exe? This has worked for some people. If that doesn't work there is a regedit that fixes it, I can't fnd the thread at the moment though.

Edit: Regedit can be found here.

According to rumors I have heard - you have to restart the game ( start new game) to see the troll dlc... Now given that the troll dlc may (and probably has) failed to install - you may replay the prologue few times... I myself have resigned myself to the fact that I got what I paid for -> free dlc promise = no dlc actually....

Sigh, I'll give it a shot, but it meas a lot of lost progress. I'm hoping the jacket will show up too.

@AutomaticMeat: Thanks for the suggestion - do you mean the patcher executable downloaded by the launcher right after installation, or something else?

Still, I think I'll wait a few days with language pack: I have the U. S. version which already is in English; the wording in the download list just suggests that the DL one may be changed (enhanced?)

I'm more eager to get myself the Polish localization; having played WItcher I in both languages I prefer the original by far (you cal almost smell cow manure when passing through the village. While the English dialogs in W2 are actually good, I am sure there is some unevitable loss of the rustically arcchaic flavor of the original.

Well, I hope the game gets enjoyable as soon as I'm through with the tutorial :)

I have searched everywhere for that patcher.exe file, i cannot find it. is this a GOG exclusive thing? I bought TW2 from Amazon

I also got a disc version, and I can't find that file :-(

Sorry for not being clear. Try C:\Users\YourName\Documents\Witcher 2\Downloads. The Patcher_ROW.exe is in there for me.