How Do I Completely and Permanently Disable Windows Defender

Windows Defender is useless, and I should disable the anti-virus program. In that way, I should never damage my computer.

I have MalwareFox (a better program than Windows Defender).

As Jacee mentioned I would be careful solely relying on antimalware to do the job of a comprehensive antivirus program.
Antimalware is good at removing specific threats that antivirus may struggle to find but not specifically viruses. You have to know what malware is and what viruses are to understand better.

A virus is something that infects your computer and then replicates itself. It doesn't HAVE to replicate itself but this is usually what they are designed to do. The most effective viruses are those that replicate across the network ie the internet. The name is based off viruses in the real world. They infect people, animals etc and then they replicate and infect others. Old school viruses were those that infected your computer, did something bad like perhaps wipe your drive or put stupid pictures on it or do something like that and then went on to infect others. Their aim was the logistics behind the operation. The virus was the transport. The whole concept was exploiting the host and getting in, much like a real world virus does. How to break down something and then infect.

Malware is a specific bit of nasty stuff that has a particular aim but on it's own is not a virus. The malware is the tool, not the transport itself. Usually malware doesn't have the stuff in it to make it infect other computers and that's where viruses come in to do that job. Malware it gets in, does the job, and then it's done. This might mean recording keystrokes, stealing personal information, disabling physical systems, controlling systems etc. A virus doesn't do this because like just mentioned a virus is generally the transport. A virus is how something nasty gets from A to B while compromising the host. Malware is the tool underneath, the usually highly specialised task it has been given.

When you understand it like this without only antimalware protection you are protecting yourself against the tools but not the transport. Antivirus will detect nasty stuff that at it's core is designed to infect your computer. It will detect attacks against your computer by things that want to get in and infect it. Antimalware will detect nasty stuff that does more than this but is not a virus itself (usually). Antimalware will detect the keylogger, the bank details stealer, the ransomware encryptor, anything that is tailoured to do a more specific job.

So you should run both. Viruses are still common although the term malware has become a catch-all for lots of things these days. However there is a difference and you should understand that so you know what sort of protection you are getting and what you need. Antivirus won't be great against the latest specific malware threats but it will serve as a comprehensive solution for generalised protection against the more common threats which are well known and which still cause damage to computers all around the world without some form of protection. Antimalware will be another weapon in the arsenal to cater for these specific nuanced threats that antivirus only offers minimal protection against. Run both and you'll have significantly more protection.

Also I'd consider getting a decent firewall too.

@Jacee and @supermammalego

WiseCare365 is my anti-virus program that I am using preferably, and MalwareFox Anti-Malware is my anti-malware program that I am using preferably.

If you want to disable it you have to make a few registry changes. Depending on how far you want to go to disable it (as there are multiple aspects of Windows Security) you may make one change or several. To completely disable everything so that it doesn't run at all and doesn't check to see if things are running, doesn't notify you etc you have to create your own registry file template that contains all the registry entries needed to disable everything.