Sometimes some third party extensions in the Internet Explorer are buggy and do not let Internet Explorer start or work normally. In such a situation, you can check by starting the Internet Explorer without the third party extensions to see if it starts properly. This is how you can start the Internet Explorer without the third party add-ons :
You should have an Internet Explorer shortcut on your desktop. Right click on this shortcut and choose Start Without Add-ons from the right click menu.
This would make the Internet Explorer start without any add-ons like toolbars, accelerator, browser helper objects etc.
You can also start Internet Explorer without add-ons from the Start Menu shortcut which you can find from Start Menu → Programs → Accessories → System Tools → Internet Explorer (No Add-ons).