^^^ That's not actually what Etch was referring to, Bert.
There are TWO things that affect the way the display on your monitor looks. Firstly, your computer has to be sending it a nice clear signal and then your monitor needs to be configured to display that signal correctly. Even if performing a 'factory reset' on your monitor has got it close to where its settings need to be, that isn't going to help if your computer is sending it a poor quality signal in the first place.
It's the 'sending' end of things (i.e. the settings on your computer) that Etch has suggested need investigating, rather than the 'receiving' end (i.e. the settings on your monitor).
As Etch has suggested, right-click on your desktop and select 'Graphics properties'. What you see then will depend upon the graphics card in your computer. I'll show you what I see but you'll probably see things a bit differently. (The principles remain the same though):
When I select 'Graphics properties', I see this:
https://i.postimg.cc/SsX6TfmN/1.jpg
From there, I need to select 'Display', to get to this:
https://i.postimg.cc/pXkmjnt0/2.jpg
Selecting 'Color Settings' (horrid US spelling!) gets me to this:
https://i.postimg.cc/dVptR2N9/3.jpg
Then I can move the Brightness and Contrast sliders to get the image on my screen looking how I want it to be.
I use this test card to check that what I'm seeing on my screen is being shown at its very best:
https://reeddesign.co.uk/testcard.htm
The six blocks of colour should each be bright and clear while, importantly, every number from 1 to 10 should stand out clearly on the bottom two lines.