If you find that the IE-8 is taking a longer time to start, it could be due an add-on that takes more time to load. Follow the following steps to find and identify such an add-on:
1. In IE-8 click on ‘Tools>Manage Add-ons’
2. You can now view ‘Load time’ of add-ons in the ‘Toolbars and Extensions’ section. If you find any slow loading add-on here, use the ‘Disable’ button to prevent that add-on from loading each time you start IE-8.