The picture shakes

http://www.viewsonic.com/support/downloads/

Make sure you have the latest drivers for your monitor installed.

Connect it to a different computer, e.g., a notebook computer,
and set the screen-resolution to 800-by-600, and see if the monitor works.
Change the screen-resolution to 1024-by-768, and try again.
Change the screen-resolution to 1280-by-1024, and try again.

Connect a different monitor to your computer,
and set the screen-resolution to 800-by-600.
Then, disconnect the "alternate" monitor, and connect your monitor.
Change the screen-resolution to 1024-by-768, and try again.
Change the screen-resolution to 1280-by-1024, and try again.

your rate of refresh is too high, it's refreshing too fast, you need to lower the screen resolution. keep in mind, the tv resolution is much much smaller than a computer monitor. a computer monitor has much higher resolution. so Tv can only handle so much in resolution. if you need a better picture, it always the best to buy a monitor, not a tv for computer to get a good picture. if you have any more questions, let me know.

The native resolution of you monitor is 1440x900. If you previously had it set at a lower resolution (say 1280 x 720) the text would appear larger than it does now. You can change the appearance of internet explorer by using the Zoom function (Ctrl +).

Honestly, that sounds like one of two things happened. Either the resolution of your computer video card changed or (I'm not sure with your specific TV) the TV's resolution changed.
If through the TV menus you can adjust PC resolution, I would try changing the resolutions. In the LG 47LB5DF TV, press Menu, then go to Picture, then go down to Screen. On the screen menu, you will see Resolution, Position, Size, Phase, and Reset. First try adjusting the Resolution to some of the options you see. If that doesn't work, try to reset the screen settings.
If adjusting those settings on your TV does not help, then you will have to change the resolution through the computer. Try connecting a monitor to the computer. If you get a picture through the monitor, on the desktop right click and select Properties. If using XP go to the setting tab, if using Vista/7, select Display Settings. Lower the resolution to something you think the TV will be able to handle, then connect the PC to the TV again. If you are using an HDMI connection to the TV, you may have to turn off the computer, connect the cable, then turn the computer back on with the TV on the correct input.
If the monitor doesn't show the picture or if you don't have another monitor, you can try adjusting the picture in safe mode, by pressing F8 after you press the power button, before you see the Windows loading screen. Press if multiple times if necessary. You should see a screen that gives you a few startup options. Select Safe Mode. After Windows boots up, you should still see the screen as the resolution would have been reduced. From there try changing your display settings.
Hopefully that info has helped. I noticed that you asked this question 2yrs ago, so I hope you have already figured out how to fix your problem. I simply wished to post this in case it would help you or anyone else had a similar problem. Good luck and take care.

You may have to match up the video card settings with the monitor settings to get the correct resolution setting. Try adjusting the resolution of the graphics card to match the setting for the monitor. If this does not work you can call, Envision customer support at this telephone number : 1-888-838-6388. They should be able to help you get the correct setting for you set-up. I hope this information helps you with your problem.

Right click on your desktop. Click on properties.
Click on Settings. Adjust the resolution based on the documentation for your screen.

If both monitors are shaking,problem is with video card or motherboard,you might try loading specific drivers for your video card or try changib=ng refresh rates.
Please rate the solution and provide feedback.
Samir

refresh rate, likely
try to adjust to a compatible rate. the monitor manual will give you its compatible rates. the video card should have that rate available. if not, you may damage the monitor with the wrong rate.
stop and try another monitor that has a refresh rate available on your video card.
good luck
mark