remove some modules

Hi! i'm trying to remove the inactive blocks from everywhere. Specifically I'm trying to remove classifieds, videos, blocks and others. I've made them disabled and no problem so far. Now what to do is that I don't want those items to appear anywhere, like they are appearing at quick stat at admin panel and user panel. I've tried commenting sitestat.inc file but however it is only working temporarily. Could anyone please help me remove these things from quick stat and menu bar??