Really, we need more information :] OK, have you installed the drivers? How long have you had it? New? What make, size? What resolution is it set to? I presume you're using Windows Vista. What GPU are you using? Maybe give us some specifications on your entire system is nice. :] What cable are you using? What refresh rate is it set to? Sorrii to throw so many questions. Answer what ou can and that'll be useful. :]
Check the desktop resolution. If it's not the correct resolution for your monitor, it'll be blurred/distorted.