Is your Internet Explorer slow when you opening pages or waiting too much for the new tab to open?
Try the following (for IE8 and IE7):
1) Go to “Manage Add-ons” in the “Tools” menu
2) See if you have Java installed by locating “Java(tm) Plugin 2 SSV Helper”, and if you found it click “Disable” button
3) check your speed now! Is it faster?
Also you can disable plugins you are not using like “Google Toolbar”, “Yahoo! Messenger” and others.