When I start to install a copy of Ad-Aware which I've downloaded from Filehippo (the same for CNet) I get a Windows message that the publisher is unknown and it hasn't been digitally signed. Is it safe to proceed?
I'd also recommend getting it from Lavasoft's homepage.
When I went to try out Nod32 just the other day that I downloaded from Filehippo.com and when using WinRAR to test the SFX RAR it stated the authenticity was corrupt, thus I didn't install it.