Many people (me also) prefer third party DNS services as an alternative to their ISP’s DNS service mainly for faster web surfing.
Here I am talking about a free, portable utility called Gooogle DNS Helper. This tool helps you instantly switch between your current ISP’s DNS address and Google Public DNS address.
Although, changing your current DNS address is extremely simple, the tool make this even simple. Moreover, you can quickly restore your ISP’s DNS address at any time with a click.
Gooogle DNS Helper required .Net framework installed on your computer for working. As it is portable no installation required. Just run it. Download the tool from coders.