But I was hacked by someone when I used eset smart security only for my old pc 2 years ago
I do not know how it happened
I searched for more protection and decided to get spyshelter firewall
But I did not tried it with eset security
Please elaborate by giving us more details.
Firstly, I am not sure about what you are referring to when you say "hacked" since you could mean a number of things - was malware active on your system (e.g. a backdoor infection), or were you attacked outside of this factor (e.g. via a DDoS attack)?
Secondly, the firewall in ESET Smart Security is actually very good - I would think it to be better than SpyShelter however this is just my personal opinion, thus why I recommended it over SpyShelter - and I would imagine that ESET do much more work on it, hence having a larger development team and arguably much more money to invest into it's development.
If you prefer SpyShelter then use the firewall component on that and if not then use the ESET one, both are good and will help to keep you protected - that's all there is to it when deciding the security software alongside already knowing the protection is good... Just go with your flow, whatever rocks your boat, and never give up on hope.
That being said, no security software will keep you 100% protected, that's impossible because you as a user can make a bad decision... Therefore, always keep your eyes open and think before you download and run something (for example).