Force IE8 Into IE7 Compatiblity Mode

If you add this to your meta tags:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7" />

IE8 will render the page like IE7.

I might have found it now. http://blog.lroot.com/articles/the-ie7-compatibility-tag-force-ie8-to-use-the-ie7-rendering-mode/

The site says adding this meta tag:

<meta http-equiv="X-UA-Compatible" content="IE=EmulateIE7">

or adding this to .htaccess

Header set X-UA-Compatible: IE=EmulateIE7 

There is an HTTP header you can set that will force IE8 to use IE7-compatibility mode.

its even simpler than that. Using HTML you can just add this metatag to your page (first thing on the page):

<meta http-equiv="X-UA-Compatible" content="IE=7" />

If you wanted to do it using.net, you just have to send your http request with that meta information in the header. This would require a page refresh to work though.

Also, you can look at a similar question here: Compatibility Mode in IE8 using VBScript

one more if you want to switch IE 8 page render in IE 8 standard mode

<meta http-equiv="X-UA-Compatible" content="IE=100" /> <!-- IE8 mode -->

A note to this:

IE 8.0s emulation only promises to display the page the same. There are subtle differences that might cause functionality to break. I recently had a problem with just that. Where IE 7.0 uses a javascript wrapper-function called "anonymous()" in IE 8.0 the wrapper was named differently.

So do not expect things like JavaScript to "just work", because you turn on emulation.