A case of deja vu as the only thing that has changed since your previous thread
here is that you have got rid of McAfee and installed possibly the most resource hungry AV program that is out there, AVG and Norton being the two most renowned resource hogs.
You have not upgraded your RAM as was advised in that thread and your present AV is most likely what is using up almost all of your RAM.
Physical Memory
Memory Usage 78 %
AVG is my antivirus software (fully licenced)
Sorry but you have wasted your money, Windows own AV Defender is one of the best that there is, it costs nothing once you have paid for Windows, it doesn't cause conflicts with Windows and it does not use up all of your RAM.
Question for you, has the RAM in this computer ever been changed, the CPU is limited to 2133MHz so shipping the computer with 3200MHz capable RAM would be most unusual.
Crucial results
Team Elite 16 GB (2 x 8 GB) DDR4-2666 CL19 Memory