This is something which has been bugging me for a while now. I noticed the first time I opened IE it seemed very slow slow to open on some of our server machines. In some cases 20 seconds or more. The second time I opened it it would open instantly.
I looked a few possible causes but in the end it was a simple setting inherited from the original template configuration. After disabling the Automatically detect settings IE was much faster to open.
Open IE, Click Tools -> Internet options -> Connections -> LAN Settings then deselect the tick box (see screen shot, click to enlarge) By the way if you cant see the tools option press ALT on the keyboard while IE is in focus.
Some networks may require proxy settings so please consult your network administrator if you are unsure of the required settings