You need to understand that no security software will give you 100% protection. But there are steps you can take to significantly reduce the risk of getting infected.
Keep your system updated with Windows Update. Keep vulnerable software such as browsers updated (your browser should do this itself).
The most common way to get is infected, is by manually opening infected files, rather than just by visiting compromised websites. As a result of this, you should always be very careful about what files you open. Never open email attachments unless they are from emails you were specifically expecting. Only download installers from the software's own website, or a trusted site such as Softpedia. If any website wants you do download software, do not do so unless you are sure you need the software. Don't open executable files from flash drives, unless you are sure they are safe.
If you every have any doubts about an exe file. Scan it a VirusTotal, to see if it is safe, before opening it. No security software will detect all threats and it is possible they your antivirus could not detect an infected file.
VirusTotal
www.virustotal.com
One problem with VirusTotal, is that sometimes safe files will get wrongly detected as malicious, by some antiviruses. But if you are unsure about the VT results, you could for example, post the VirusTotal link here and get other people's opinion on if they think the files is actually infected or not.
Just by doing the above steps, it will be very hard to get infected, no matter what security software you use. It's much more important to take basic steps to protect yourself, than obsessing about having the absolute best security software.
Also, it's very important to keep regular backups up your system. That way if you your system does get infected and data gets encrypted or deleted, you will have recent backups to restore from. Aside from that, having a full backup of your system, lets you easily restore your system to a working state with all your apps and data, if your hard drive or SSD fails and you need to replace it.