Change the default search engine in Internet explorer
Default search engine of Microsoft Internet explorer is MSN. But there are better search engines available. I like yahoo.com and you may have your own preference.

Open registry editor by going to START-RUN and entering regedit and navigate to following three keys separately and change it as shown below:

[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\Main]
"Search Page"="http://www.google.com"
"Search Bar"="http://www.google.com/ie"
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\SearchURL]
""="http://www.google.com/keyword/%s"
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Search]
"SearchAssistant"="http://www.google.com/ie"
(This example is specific to google but there is a Microsoft article that I found on their support site which described show to do it for many other engines.

Read all of it at:

Change IE default search engine

enjoy