I just ran into a browser hijacking that wasn’t repaired by AdAware. “LuckySearch” came up as the browser home page and default search engine every time the system rebooted, even after a thorough cleaning.
It turns out there’s new methods of hijacking a computer that are even more insidious than the adware and spyware addressed by AdAware. This page describes the “CoolWebSearch” variants and provides a removal tool. It solved the problem on the system I was working on (but I can’t vouch for it – use it at your own risk).