Set Google Toolbar to prevent save your
search History.
If you are using Google Toolbar with your browser, you can customize its option using
setting button. Google toolbar search box save all your last searches keywords history.
You can clear the saved history by clicking on the "Google" button on the far left.
From the menu, select "Clear Search History".
But if you want to prevent the Google toolbar from saving
these searches permanently
then click on Google button and choose
options from the menu. Here choose More
tab option then deselect the
Save the Search history across browser sessions.
Now Apply and click Ok
button.