These pictures look like your monitor is attached to the computer via a VGA cable, using analog signals.
If there is no possibility to switch to a digital connection, such as DVI, HDMI or DisplayPort, I’d first recommend adjusting your screen.
Most monitors come with an Auto Config feature to automatically adjust for best quality when using VGA. Please refer to your monitor’s manual.
Alternatively, you can play with picture settings, such as “Clock” and “Phase” in order to get the best quality possible.
However, the best solution still would be using a digital signal connection to the monitor.
As using a digital connection does not automatically improve font rendering in all cases and in all programs, I also did a few tweaks in order to improve it: Firefox Nightly 86 and VDPAU / Nvidia - #7 by DAC324