The crack downloaders basiclly let you search for cracks are serial numbers from a mass database that is updated with new cracks for different programs pretty much daily. CrackDownloader 2.2 is the older one but still runs on the same databa. 3.0 is the new one it is alot better but has alot of errors and very commonly doesn't work for people. So don't be discouraged if it doesnt. I suggest trying 3.0 first then if not then 2.2 should work for you.
Note: Since these run from a crack and serial databasse you virus scanner might pick these up. Just pause it or w/e