"no update available" as it can't find any sites providing updates.
that can be because it isnt able to resolve the path to the update site..the prog does give you a small selection of D/l sites..try them.. when I have that issue.. I will try the same link a few times before trying one of the others.. if that fails I have a problem with the clients machine..

Hijack This - is your last resort, it is a powerful spyware removal tool but it can easily cripple your system
Actually it isnt that powerful.. MSCONFIG can do the same damage, so can several of theearlier progs you have mentioned..

DONT write of a helpful tool that easily.. and I would never recommend it as the last line of defence (well removal)
Advise SCAN ONLY to clients.. save the Log and LET AN EXPERT ANALYSE the log.. DONT LEAVE THE CLIENT TO THEIR OWN DEVICES WITH ANY OF THESE TOOLS.... the damage can be as sever or worse than what is already in the machine..