I'm using a popular website script that I've changed the html/css and it looks great in IE8 and IE9,
but it seems many changes are needed to make it look good in IE7.
The IE7 pages needs to be much, much wider apparently, and div's overlap, etc. Why such a discrepancy?

The header file (of the wscript) it shows this line:

<!--[if IE 7]>
      <link rel="stylesheet" href="[var.base_url]/[var.user_theme]/css/ie7.css" type="text/css">
So, I've been making changes to the IE7.css file, but it seems endless. Is there a better, easier or more efficient way to go about this?