How to use google.com as my default search engine

I have my little problem with my Google search engine. I wanted to use Google.com as my default search engine but I keep getting "google.com.ph" every time I search. I feel that it narrows my search option so I really wanted to fix this. How can I delete .ph and just use google.com? Is there any way to solve my problem?

By the way, I use Google Chrome as my browser. Just in case someone would ask.
