How can I re-instate my progress in the game which seems to be lost?

[zachofalltrades]

In other words, I havnt played inawhile, I changed computers and os and want to play again. I kept the old harddrive with the steam folder and run steam and other games from that folder, np. I can see my old score and achievements but my trench and weapons are not appearing and the only option is new game!!!!!!!!!!!!!!!!!!!!!1