You can also click on Search > Permissions & History in Settings. Scroll down and find History in Bold. You can toggle search history on or off here. To clear your search history, click on Clear device search history.

In the toolbar at the top of your computer screen, click Chrome. Click Clear browsing data… Select a time range and the history you want to delete. Click Clear data.

You can clear the history of searches you made through Google Toolbar. This won’t affect your Internet Explorer or Google Search history. Open Internet Explorer. Go to the search box and click the Down arrow. Click Clear History.

To clear the Google search bar history on your mobile device, launch Google Chrome on your phone. In Chrome, tap the address bar and start typing your query. When you see the suggestion you want to remove, tap and hold on it. Tap "OK" in the prompt. And your selected suggestion is now removed.

In the past, my advice was to hit the options button on the Google Toolbar, turn OFF Drop Down Search History and press OK. Then repeat that process to turn it back on, after which the history appeared to be gone. In later versions of the toolbar it’s way easier. Click on the Google logo, and then click on Clear Search History: