A good idea to see if there are pixel errors is to use the paintbucket in paint with for example yellow or red as color and see if all parts that are connected with the same paint get red or yellow and then you press ctrl z to restore so you can change any pixel that was wrong and then go on. I hope you understand what I mean
Yes, that's the way I try to eliminate pixel errors. I've discovered that changes still happens. Even if I go into the colour sceme and choose real black there occur grey pixel in the lines (and other pixel errors too)
I guess my pc is to old and autonom and need to be replaced. That's on my personal wish list