well i can see the very same lines on the upper right of ur screen...the color lines on my screen are way harder than urs...it may be a windows problem...lets see if anyone knows whats going on
I don't think that there are any lines on here that aren't supposed to be. They are all part of the design.
Click on the desktop, select Personalize and then select the Windows Classic Theme (it has a solid color background) and look at the desktop and see if there are any lines showing on that.
That looks like a normal Windows background to me. Why don't you pick a different theme?