I have installed COMODO Firewall and I have some knowledge about internet security and i set up my firewall rules so my computer is protected enough (that really doesn't matter in current context). The question is: Do I really need Windows Internet Protocol Security (IPsec)?
I would ask, how do you think you are using IPsec? Between what hosts would you be using it? The chances are you have zero reason for it. IP sec is used on internal networks to make sure that people can't use programs like Wireshark to capture and decode packets. It requires both ends of the connection to agree to use it.
As you browse the Internet, and use other protocols out there for different applications, those foreign hosts are not going to be setting up IPsec tunnels with you. A VPN may use IPsec, but I think that is mostly site-to-site VPN's, not the type you might commonly use, and they have their own methods of encryption.
So if you are on a home network, and you REALLY think that someone can physically tap into your network, and REALLY has the desire to run a protocol sniffer, then by all means, set it up. Of course, the chances of that are 1 in a million, so buy a lottery ticket too.