How we can operate volume control buttons of monitor HP w1907

You read the manual here it tells you how to push the volume button.

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00850059&tmp_task=prodinfoCategory&cc=us&dlc=en&lc=en&product=3351967

But you can't mean that. Can you?

There is also some software that may allow you to set volume from your PC

My Display Software
My Display software can also be used to set the monitor for optimum viewing. Select settings for gaming, movies, photo editing, or documentation and spreadsheets. To install My Display software:

Insert the CD in your computer CD drive.
A menu displays.
Select the language.
Click Install My Display Software .
Follow the onscreen instructions.
Restart the computer.