web site graphics do not load when upgrading from IIS 6.0 to IIS 7.0

<div class="body">We are upgrading web sites from Windows Server 2003 R2 to Windows Server 2008 R2. Web sites that worked in IIS 6.0 do not work in IIS 7.0.  The issue is JPEG graphics do not show up. We just get the red x's in the boxes. We copied the files over from the 2003 server to the 2008 server and set up IIS the same (we think). Is there a DLL issue involved or could if be something else?</div>