how to delete the history of the sites visited?

I use CCleaner from Pirisoft (free) to regularly tidy up my PC, including deleting History from all the browsers I happen to use. You can tell it exactly what elements to remove (though it can't deal with, for example, just the last two hours' History) and it also empties your Recycle Bin, removes temporary files and can check your Registry for anomalies. I run it, generally, at the end of a session, before I close Windows, so that when I start a new session, I know that there is no redundant junk to slow me down.

one very easy solution - download and run CCLEANER - its free and will delete all temp files and history and other junk files. also cleans registry. gives few more options if u want to use. using it for 3-4 yrs, pretty handy.

One of the best discussions. :) Learnt a lot from it. :) Thanks. :)

A nice trick for Opera (don't know for Chrome): The latest versions of Opera let's you perform a "portable" installation, basically meaning that everything related to it will be contained in a single folder and not scattered across the whole disk as most browsers do. If you want to protect your privacy, you can do this kind of install to a folder where only you have access, or a pendrive. And use that copy safely and independently of any other browser, knowing that no one will have access to your history.