Question Why is my monitor flickering like this?

[blizkit89]

This is a old PC. My old monitor also used to do this. This is a new LG monitor connected via VGA.
Intel Dual Core E5200
4GB DDR2 RAM
Intel DG41RQ Mobo
PSU 450 watt.
1TB HDD. 400GB free.

LG MP68VQ

New as of one year. My mobo has problems. My onboard audio is damaged so I use a USB audio converter.

https://imgur.com/FdARZmF

 

[Ralston18]

Old PC....

Update your post to include full system hardware specs and OS information.

PSU: make, model, wattage, age, condition (original to build, new, refurbished, used)?

Disk drive(s): make, model, capacity, how full?

Monitors (old and new): Make, model information?