Question Pixel (image) noise on NEC monitor !

[Br_Pay]

Hello there....if someone can help me to deal with this

I have a NEC monitor with this model : SPWPUB24

I usually use it for my PC...but I've got a weird screen, specially when I set windows 10 background wallpaper to black color to see if there are or not !

but there is no problem with the other PCs and I haven't got a weird screen during the work with them actually with the best quality of the picture .

Could be from the Graphic card or power supply ?

Graphic Card :
ATI Radeon HD 4300/4500 Series

Power Supply : ELEGANCE 350W

1680x1050 this is the max resolution of the monitor


Let me Know ...thanks