you should put a cushion on your back and every half hour stand up and move about.
You should use the proper way of sitting when using computer.
It is good to look at a distant object now and again while using a computer helps because when you are just focusing on a computer screen all day your eyes start to hurt and get tight, but every hour or so you should look at something far away , it will get your eyes back in focus.
How to get your computer screen back to factory settings ( back to the new one) should be part of the help pages of the computer
Cleverbot
You should always back up your computer files just in case your computer decides to go kaput. When you back up your files on another drive, you can always have access to them.
Your back should be the main support for your body while sitting. It is important to maintain good posture to prevent strain on your back muscles and spine. Using a chair with proper back support can help you sit comfortably and maintain good posture.
It depends if it is wireless or with a cord. If it has a cord, simply plug it into the computer using a usb plug on the back of the computer. If it is wireless, turn off the computer, turn off the mouse, turn the computer on, wait for the computer to ask for a mouse, then turn on the mouse, and the computer should pick it up within a minute or so.
I'm afraid you'll have to be more spefic. I could say heart failure and have it be correct. Short term effects of using computers can include arthritis and carpol tunol. Along with back problems if you don't have good back support while using one.
You should try rebooting it. (Turn off the computer and turn it back on.)
the best way to back up data on an android is to connect it with a computer using a USB cable and saving them in the computer
plug your sd card into a computer and drag files into it using iTunes windows media player etc... then plug it back into your dsi and they should by there
put in flash, go through start and programs tell it you want to say to flash, it should have instructions for you to follow