IE Stylsheets/ Conditional comments Not working

Here is the correct format of the comment:

<!--[if IE ]>
Special instructions for IE here
<![endif]-->

here is a NOT IE comment:

<!--[if !IE ]>
According to the conditional comment this is not IE
<![endif]-->

source: http://www.quirksmode.org/css/condcom.html

edit: just noticed that their 'not' example is wrong. i have corrected it.

You should use like this : Syntax :

<!--[if IE 8]> = IE8
<!--[if lt IE 8]> = IE7 or below
<!--[if gte IE 8]> = greater than or equal to IE8


<!--[if IE 8]>
<style type="text/css">
    /* css for IE 8 */
</style>
<![endif]-->

<!--[if lt IE 8]>
    <link href="ie7.css" rel="stylesheet" type="text/css" />
<![endif]-->

reference link 1

reference link 2