We are dealing with this issue. Nessus along with a few other tools have been part of our kit for a while. Now there is a work around form what here that does not involve a more complex home network. there is supposedly a company that will be publishing plug ins for nessus for free becasue they are upset with Tennable.
I just got done playing with LANguard and I felt that it left things unfound and had a few too many false possitives for us. Namely, it was telling me in our lab that on one of the machines that ports 21, 25, and 110 weree open. After checking both the machine itself and using nmap, the ports were all closed. It also missed bo2k. With that said, I would be careful with whatever tool you decide to use.
CompTia Security +