Well since I do tech support all day on the phones at work for a living.. which im doing as we speak.
Basically windows keeps most parts of internet pages in it's history to sort of speed things up (more plausable when everyone had dialup)
So after collecting pages, it checks this history to see if it has the page, or the latest version of the page, if it finds it on the hard drive, it loads it, if not, it downloads it and saves it.
So basically when you have a few hundred, it's that finding a needle in a haystack type effect where it takes so bloody long to rifle through all those files, it seems to take so long.
So do the following to get rid of them
(yes, I've done this thousands of times with great results every time)
Go to start, settings, control panel.
double click on internet options.
click on delete files, and put a check in delete all offline content then click ok.
Then click on clear history. then click yes.
then click on settings, then view files.
You'll see a box with your cookies in it.
click edit, select all, then delete on your keyboard then click yes to delete all the files.
then click ok on both windows and you should be back to your desktop.
Open up Internet Explorer and enjoy.