I found a solution whoever comes acroos the disappearing scrollbar in IE10 and has a responsive theme simply add this code to the header.php:
<!DOCTYPE html>
<!--[if lt IE 7 ]><html class="ie ie6" <?php language_attributes();?>> <![endif]-->
<!--[if IE 7 ]><html class="ie ie7" <?php language_attributes();?>> <![endif]-->
<!--[if IE 8 ]><html class="ie ie8" <?php language_attributes();?>> <![endif]-->
<!--[if (gte IE 9)|!(IE)]><!-->
<html <?php language_attributes();?>>
<!--<![endif]-->
<!--[if !IE]><!--><script>
if (/*@cc_on!@*/false) {
document.documentElement.className+=' ie10';
}
</script><!--<![endif]-->
This creates a an ie10 class in the html tag which you can call in your css sheet. Simply add:
`
html.ie10 {overflow-y: scroll} to your style.css and scrollbar stays and does not disappear anymore in IE10 and yes you can add more classes for specifically IE10 the same way.
IE10 does not respond to the conditional tags anymore as we knew them.