Internet Explorer 8 uses a resource allocation scheme known as "Loosely-Coupled IE." What this means is that tabs and add-ons are separated from the primary Internet Explorer process. This segregates these resources so that if one should become unstable, you can close it without having to close Internet Explorer. It is also supposed to prevent Internet Explorer from grinding to a halt in the event that a single tab crashes.
The amount of CPU power that Internet Explorer uses depends on the number of tabs you have open and the add-ons that you are using. The program freezes when one of these add-ons or tabs becomes unstable. By learning more about Internet Explorer add-ons, you can gain a better understanding of how to manage them so you can prevent freezes.
Internet Explorer Processes
However, segregating add-ons from the main Internet Explorer process does not guarantee that Internet Explorer will never use 100 percent of the CPU power. In fact, if you have a corrupted or poorly performing add-on installed, Loosely-Coupled IE will do nothing to improve its performance. What it will do, however, is provide you an opportunity to handle these add-ons on a case-by-case basis. For example, if you have many instances of the Flash plug-in running on your computer at once, you can easily use 100 percent of your power and bring IE to a halt. Fortunately, there is a quick fix for this situation.
To bring Internet Explorer's CPU usage down, simply right-click the Taskbar and then click "Start Task Manager." Click the "Processes" tab, and then click the "Memory" tab to group them from most memory intensive to least. You will see many instances of the "iexplorer.exe" process. Each of these corresponds to a tab that you have open or to a particular add-on. To close frozen tabs and reclaim your CPU, simply select the top-most Internet Explorer process and then click "Kill Process." Internet Explorer itself will not crash, but it will close the offending tab. Repeat the process if there are several "iexplorer.exe" processes using a lot of memory.
Testing for Faulty Add-Ons
Closing add-ons that claim all of your CPU power is only a temporary measure. To prevent the problem from recurring, you should disable your add-ons one by one to determine which of them is causing the freeze. To do this, click "Tools," and then click "Manage Add-ons." A list will appear containing the add-ons that you have installed. Select the first of these, and then click the "Disable" button located at the bottom of the "Manage Add-ons" window. Click "Ok" and then use your browser as you normally do for a few minutes. Then, return to the list and disable the next add-on. Continue in this fashion until you have either found the offending add-on or have disabled them all.