MW2 and MW3 were recently split from Call of Duty HQ in our libraries and this wasn't a smooth transition for all of us. If you are like me, your achievements did not immediately appear after launching the standalone games for the first time. I was able to unlock all achievements by playing through the missions again except for the Gentleman Thief achievement.

Here is how I was able to sync my achievements and fix this bug. If this guide is helpful at all please consider dropping an award :)

I know it sounds absurd, but trust me. Uninstall and reinstall, but follow these steps below to ensure it syncs properly. For whatever reason the order and methods I tried before had me replaying the entire campaign over and over. Here is what to do:

1. Uninstall EVERYTHING! Get rid of Call of Duty HQ, MW2, and MW3 (if you are syncing this also).
   
   
   
   
   
2. Before reinstalling everything, ensure you have all DLC for MW2 (and MW3) enabled in Call of Duty HQ.
   
   
   
   
   
   
   
3. Once the games are reinstalled, launch Call of Duty HQ. Let it run its automatic updates until you are left on the home screen.
   
   
   
4. Close Call of Duty HQ and launch MW2 (or MW3), and the achievements should sync!
   
   

If the previous steps did not work, you can also launch Call of Duty HQ and navigate to Settings > Account & Network Settings > Sync Achievements



Relaunch MW2 (or MW3) and the achievements should pop!

Did I enjoy the campaign crashing my PC in 3 different missions and the same persistent lighting bug during my play through? Kinda.

Did I enjoy replaying Alone 5 more times to try the safes for the Gentleman Thief achievement? Not one ♥♥♥♥♥♥♥♥ bit.

Did I enjoy replaying El Sin Nombre 5 more times for the safe? Every ♥♥♥♥♥♥♥ second. Valeria has me weak.



Image from The Logman

That is all, I hope this helped you. If it did I kindly ask you to consider dropping an award or a comment for the algorithm. If it didn't, sorry fam.