If you read all my posts in this thread you will understand why I do NOT NEED virus protection, ever. Have been doing business transactions on-line since Windows 95 came on the scene, and no virus has found me since. My methods allow me to run a computer so much faster with ZERO virus protection, and surf the net to my heart’s content.
My business computer has SSD and is slower because of virus protection programs, but I use it like average 10 minutes in a day to execute a stock transaction or make bank transfers etc, so speed is of no consequence.
I ran Windows with extensive Internet use for years with only 2 viruses (minor) just using "pray and press" and free mvps host file. But when i went to W/10 Pro (retail upgrade path from Win. 8) then I have left the Defender on, but it does not use much CPU cycles.
For those who want to, is this how you did it:
Open Start.
Browse the following path:
HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows Defender
Quick tip: You can now copy and paste the path in the Registry's address bar to quickly jump to the key destination.
Right-click the Windows Defender (folder) key, select New, and click on DWORD (32-bit) Value.
Name the key DisableAntiSpyware and press Enter.
Double-click the newly created DWORD and change the value from 0 to 1.
Click the OK button.
Once you complete the steps, the Windows Defender Antivirus will no longer protect your system against malware.
If you want to revert the changes, you can use the same instructions outlined above, but on step No. 6, right-click the DisableAntiSpyware key and select the Delete option.
From windowscentral.com How to permanently disable Windows Defender Antivirus on Windows 10