Here are some of the free utilities that I use.
I have used Avast Home antivirus software for several months. I have found this to be an excellent product and would recommend it. It is free for home use, you just have to register it every year for free.
I used to use the old version of Kerio Personal Firewall, but a couple of months ago, I found Comodo Firewall Pro . This is a free for life firewall that is regularly updated.
For spyware removal, I have used Lavasoft’s Ad-Aware SE Personal. This again is available free for home use.