http://www.google.com/options/defaults.html

Internet Explorer

For Windows: Download this file to make Google the default search engine for Internet Explorer versions 4.0 - 6.0. (Note: you will need Administrator privileges on your computer in order to install this file.)

The "search" button will bring up a Google search box down the left side of your browser.

The "Search The Web" menu option from the "Go" menu will take you to Google. For IE4 only, you can type "? <search terms>" in the URL box instead of a URL, and it will perform the search.

When you click on the above link, IE will ask you whether to open or to save the file. Select "open" to immediately make the changes (i.e., to make Google your default search engine for the actions described above). Select "save," and then look at the file under Notepad, if you'd rather examine what the file does first. Be aware that you will probably have to reboot your system to make the change go into effect (even if your computer does not tell you so).

By default, Google will show results in the search channel window, leaving the main window for browsing. If you prefer seeing the search results in the main window, try this file instead.

If you change your mind, this file will set the search engine back to the original Internet Explorer default.

If you previously had your default search engine for Internet Explorer set to be Google, then you upgraded your Internet Explorer version and now find that Google is no longer your default search engine, don't panic! Just download the conversion file again to set Google as the default search engine for your new Internet Explorer version.