Step 1: Go to your steam folder and then steamapps.
Step 2: go to your common folder and into modern warfare 2, and then your players folder and delete all your STAT files.
Step 3: Now back out to your steam folder and go to userdata and go into the random numbers folders untill you get into the remote folder, then delete the two files in there.
Step 4: MAKE SURE YOU PLAY A TEAM DEATHMATCH FOR ATLEAST 10 MINUTES. Preferably the whole game unless it wasn't 10 minutes long.
Step 5: Now exit out of MW2 and restart steam and it should work.
try that c: