Left 4 Dead 2 Discussion
"C:\Program Files\Steam\steamapps\common\left 4 dead 2\left4dead2"
Or similar path (C: may be different for example)
In here, open the "steam.inf" file with any text editor (like notepad) and see what it says next to "PatchVersion". As of today, it was 22.214.171.124 for example).
* Updated game trainers and cheats daily
* Get notified when new cheats are added
* Request which games get new trainers
* Priority support with any problem