My new video card is not working right?

I just installed my new ATI Radeon video card in my Compaq Presario and either the screen has all these lines and waves through it or else there are lines coming off each of the icons, I can't get the screen to look right, I've tried all the settings available and it won't straighten out. Thank you, hope someone can help.|||well you are gonna have to insert the videocard correctly.|||could be a loose cable that goes to your monitor