My website looks different in IE7 compared to Google Chrome, I know everyone has this problem and if I was to upgrade to IE8 I probably wouldn't have any problems but my visitors may still be running IE7 and I cant force them to change.

It only seems to be fonts and size which seems to be different and I dont know how to put it right, any suggestions would be good please, link is in sig.

Are you using a CMS because it's generating some ugly code and broken tags. Anyway to fix your problem you need to define a heading 3 font size....
h3{font-size: 16px}

no I think thats me, could you give me an example of ugly code I'm fairly new to this, thanks for the tip

Ok I'll go through it with you.

Here at line 105 to 110 you have the following.

<h3 font-size: 14px align="center"><font face="Verdana, Geneva, sans-serif">
    	      <align>
  	      </font><font face="Verdana, Geneva, sans-serif"><span class="mainheading">Electri</span><span class="fire">Fire</span><span class="mainheading"> Limited - Electrical, Fire &amp; Security - All Under One Roof!</span></font></h3>
    	    <h4><br />

  	        </h4>
  	      </div>

You should just have your <h3> tag with no params and then style it with css. Also you shouldn't be using <font> wrap it in a <span>. You have a broken <align> tag which is not a valid tag anyway. Finally you have a break wrapped in h4 tags which is messy.

The following code is nicer but can be improved even more by giving your elements class names and styling in your css file like you have done with your mainheading or fire elements..

<div style="text-align:center; padding-bottom: 15px;">
<h3 style="font-size: 14px; font-family:Verdana, Geneva, sans-serif"><span class="mainheading">Electri</span><span class="fire">Fire</span><span class="mainheading"> Limited - Electrical, Fire &amp; Security - All Under One Roof!</span></h3>
</div>

thanks I'll make those changes shortly

Ok well I made those changes to the heading to start with I need to do the H4 this is what I changed the H3 to:

<p class="mainheading">Electrifire - Electrical, <span class="fire">Fire</span> & Security - All Under One Roof

However when I vie this in IE7 the font is correct but the size isn't why would that be?

Ok, for one thing the FIRST heading on your page should be an H1 tag -- and it DOES matter. Do NOT choose an Hx tag because of it's size, use the RIGHT tag and style it with CSS as you need to. You also should not be styling paragraph text to serve as a heading, use the proper Hx tag.

This is just proper, semantic document structure and the search engines DO give weight to heading structure, an h1 being more important than an h2, etc., etc.