Hardware and performance

Hi, I'm using a server Windows 2008 R2 and Moodle 2.5.2 for Windows, when I try to load my Moodle web site, by Internet Explorer 10, I must wait some seconds, about 30, to to get the display on the home page. This does not happen if I use Firefox 24, Chrome and Opera. What's happen? Which kind of configuration I must set to solve this problem? In Italy IE is the most used browser yet, so I need to take it fully functional. Thank you Sandro