This is awarded after completing the first level, the first time you make tinker dance. Unless it glitches... it may pop the wrong achievement or it may appear on your profile locally and then disappear. The solution to either problem is the same.
Others have suggested playing on a second computer, but if you don't have access to one, this solution should work.
Before starting the game, locate your save game file in your "My Documents" folder. It will be a .sav file with a lot of numbers and your gamertag. Move this file to another folder or just drag and drop it onto your desktop. Now start tinker and play tutorial level 1. Complete it and achievement unlocked! Now copy your save back into the "My Documents" folder to restore your progress. If you copy it back in while Tinker is still running, you may crash the game, but your achievement is fine.
Aerodynamo's comment on another solution was worthy of a solution in its own right, I just expanded on it and posted it. He definitely deserves a tip of the hat for this solution.