Sometimes the screen shake, I would like to ask why

My computer is a Hewlett-Packard t408cl, five or six years ago to buy a graphics card is GForce4, 64M dynamic sharing

since a few months ago the system re-found the screen sometimes jitter, is on both sides to the middle The kind of shaking, degaussing will be of no avail, have been used in the refresh rate is 85Hz, the computer has been put in the same location, the system has been installed on site with one of these things have not changed will

The following is not a cause?
1, the machine has its own old age are now used to
2, after the heavy equipment from the Hewlett-Packard's Web site to download a combination drive is not installed This has caused? In the past and I are, respectively, after re-install the driver, now plans easier to use directly from HP, where a combination of drive

50 sent, please do not use copy-paste, which answer some I see a lot more, I will not be sent to this answer.
Hope that the answer is targeted, oh, thank you ^ _ ^

ask you what the CRT display? it should be! I
of a similar phenomenon also occurs ~
I was not at home, his family said to be listening to someone I do not know the keyboard is a mouse, he pulled out directly to the shutdown did not.resumption of the boot when the water ripples Until the machine to start when the normal desktop
, not a period of time.
Your monitor or near the transformer useful things not (for example, with the cat, or speaker) is also possible.
If other circumstances I do not know.Blank space on the computer click the right mouse button to set the election in the election attribute it to have a high-click it and then inside to find the inside of the monitor screen refresh rate of just under pick.