Steam – Is possible to get the SecuROM/GFWL Activation Key after the March 19 update of GTA IV

From the more info link on http://www.humblebundle.com/

On your download page, you can optionally get a key to redeem your Humble Bundle #2 games (first shelf) on Steam and / or Desura. Not all of the games are on Steam yet: Cortex Command and Revenge of the Titans will automatically be added to your library once they make their Steam debut.

I had the same problem, and I really have no idea why it happens or how to fix it. I have, however, found a workaround. I tend to just do this from the get-go instead of actually using the setup, because of weird issues like this.

1. Don't run the disc setup; instead, activate your CD key manually, and abort the actual installation process.
2. Open the backup window (Steam → Backup and Restore Games…).
3. Select Restore a previous backup.
4. Browse to the drive letter of the installation disc.
5. Steam should tell you that it found a backup of Modern Warfare 3. Click next.
6. The game will install from disc.

This has worked for me with MW3 specifically, and other games.

Note that you can't entirely avoid downloading it; you'll still have to download the latest patches to bring your game up to date.