does anyone know why my screen looks like windy rain?

there are like, faint lines running from the top right to the bottom left corner of my screen like a windshield in a car. Does anyone know anything about this?
It's not really affecting my computer's performance...

 

It depends on what type of monitor it is.
If it's one of the LCD monitors or one of the older CRT
types. First, make sure your video cable isn't too near
any power cables. Next, make sure your connections
are tight.

 

i checked everything its still rainy. i even degaussed

 

Nearby flouresant (sp) lighting can do it.

 

On a LCD screen this can be caused by having your fonts
rendered with smooth edges.
I assume you use XP
Right click the desktop
select properties
select appearence
select effects
disable font smoothing and other effects