Luca Gallo wrote:
I have a monitor 17 '' CRT.
When i use it for many hours I see that the image begins to tremble. I have
tried the function DEGAUASS but nothing has happened.

There might be a fan or other piece of equipment near the monitor creating
a magnetic field that is affecting the deflection.
Next time you see the trembling in the image, see if you can move the monitor
or the offending equipment away from each other.

--Winston