A side effect, though, is that Google on March 1 will combine all of the search history it has on you with all your various profiles from Gmail, Google Docs, Google+ and other services to better target ads at you.
Further, your records are still available for law enforcement and Google hangs onto everything for 18 months, according to its terms of service. For more information, check out the Electronic Frontier Foundation’s excellent article on this.
Back in 2006 the EFF published this white paper with six tips for retaining your privacy in the face of search engine collection. EFF reps say it remains relevant. Find that here.
First sign into your Gmail account or other Google ID. Then, type in or cut and paste the following into your browser bar: https://google.com/history
Hit Enter. This will display the following screen.
Click the option to Remove Web History. Google then will display whether you want to clear all your web history for the account you signed in with.