Browser helper object removal?

Ive tried every free program out there avg, avg anti spyware, avg anti root, spybot s an d, adaware, hijack this, killbox, spyware blaster yada yada yada. Ive followed lots of advice given, all these products detect the bho but they cannot rename, quarantine or delete the offending file. Ive tried manually as well with the same luck. Any ideas?