Adding custom screen resolutionto Linux Mint, Ubuntu, MXLinux etc
Whenever I installed Linux distributions such as Ubuntu, LinuxMint, Linux Light, Lubuntu, MXLinux etc on old Dell Desktop PC's, the maximum screen resolution was 1024 768, I found this simple solution to add new screen resolution and make them permanent. It means, you will not loss custom screen resolutions after restarting your system. I have tested this method on many Ubuntu based Linux distributions and it works for me.