Yes there is a way, but it will erase everything meaning you will lose you're prestige level and have to start all over again.
I assume you are using steam if not correct me,
Right click on mw2 multiplayer then click local files then click delete local files, then after installing play a mw2 multiplayer game then quit after that wait for steam cloud to update then it should save your progress so thats the only way to do it that I know of.
Hope this helps.