Nice points JP56.
If you want a safer PC, (less malware) you have to understand any AV is only a part of your security, and sadly despite all the marketing hype, it is the less effective one. Good to have, but really not that great if you rely only on it.
So you must think in terms of layers of security.
Limit the possible damage of malware
* Use a Standard Account/UAC on high
* Separate the OS from vulnerable or possibly malicious applications : Sandboxie, Virtualization (VirtualBox)
Detect and block malicious software
* AV on real-time protection : Windows Defender
* Use online AV when installing new software : VirusTotal, Jotti
* Use Anti-Executables that only allow what's already installed on your PC and block the rest : Parental Controls, Applocker, Software Restriction Policies
* Make sure any newly installed software is authentic : Digital Signatures, Google for its hashes
Make your PC less susceptible to vulnerabilities
* Frequent update of the OS and all 3rd party applications : Secunia, Windows Automatic Updates
* Use tools to counter exploits not patched yet : EMET
* Disable/Uninstall any application/feature which is often targeted by exploits if you don't need it : Java, Plugins, Adobe Reader, Macros in Office documents, etc...
Reduce the downtime in case something happens
* Learn to use the built-in tools : Restore Points, Refresh, etc...
* Use a 3rd party disk image application and back up on an external drive : Macrium Reflect Free, Paragon Backup and Recovery, etc...
* Separate your Data from the OS/Programs by the use of partitions.
As you see AV is only a small part of what's possible, and I limited myself to what's relatively easy to do with only free or built-in apps.