How do you get rid of the lines you get on a picture when you take a pic of a pic from the computers screen and it puts lines on it?

you cant do this with a external camera. but, on your computer there should be a button towards the top right corner that says prnt scrn or print screen. hit this button, then go to paint, and click the dashed line box, and right click and paste. and you will have a jpeg pic of your screen. if your trying to record the screen. you can use a program like manycam, webcammax, or camtwist to record. hope i helped