Drupal 7 IE8 Crashes on website load
I've had similar issues with this, but unfortunately there can be a number of causes. Here are some things to check:


Do you have any modules that utilise flash installed? There are some issues with certain versions of Flash player that show up on 64-bit versions of Windows with IE8. If uninstalling modules that use Flash fixes the issue, then at least you know more about the problem.
Do you have CSS optimisation/aggregation turned on? If yes, try turning it off, then see if IE8 still crashes. There is a bug of some sort in the Drupal CSS optimiser, that means that if a CSS page the site is requesting returns a 404 error, then turning aggregation on will crash IE8. If you can, load up the site in another browser and use developer tools (like Firebug, etc.) to see if any of the CSS files are not being loaded. It is probably a good idea to check this regardless of whether you have turned on CSS optimisation.
Do you have JavaScript optimisation/aggregation turned on? If yes, try the same steps above, but for your JS files. Sometimes complicated JavaScript files cause IE8 to crash too.


Since you say it's a new site, I'm guessing the problem might be related to #2. Best of luck.