ZoneAlarm is a complete pain in the butt. Completely unnecessary to boot.
Spybot has been rendered totally obsolete. It used to be good, but it has fallen by the wayside and been completely stomped on by it's competition. HJT is pretty much useless now too. Almost completely, but not quite. Unnecessary, however, most definitely. There are much, much better programs out there that do the same job and a whole lot more far more effectively than HJT. HJT was bought out, so there are no longer any updates to it, rather it has been assimilated into a commercial package. Ad-aware has also been rendered obsolete. It's time has come and gone as well.
As with anything, as time passes something inevitably surfaces that is superior. For a while it was Ewido. Then Prevx1 came out and destroyed Ewido. In antivirus, Norton used to be superior. Then Panda came out and spanked it silly. Then companies realized the need to release free AV's, and you got the likes of AVG. Then AVG got spanked silly by Avast! Something newer will come out that will spank Avast! eventually. That is just the way the industry works.
There is no point in keeping a closed mind and clinging on to the past, because you are just rendering your computer open to new infections by your foolishness. It is a continually growing, moving process and you have to constantly do your research and stay on top of it (without hanging on to silly notions and ideas to justify ignorance).
Constantly keeping abreast of the industry by reading on here of the ones that obviously know what they are talking about and have done their homework will help you to stay abreast of the trends and maintain the maximum protection for your PC.