dll error

[TheCost]

Tracker error: TrackerUi.dll is invalid, not loading.

It won't go on after it was written.

 

[Skyrider]

Do you use Steam? I have a feeling you don't:

Well that's your problem! You are not using Steam! Steam is required to play this Open Beta. Click This Link and look in the right, and click "Free Download". Once you downloaded, install Steam, and register an account. Once done, go to "Game --> Activate game" in the Steam Program and use your half-life serial key to activate your account completely in order for you to download Half-Life for free.