How to set email account in outlook 2007 as default email client.

I have office 2007 installed in my windows pc. Now I have an email account to set it in outlook 2007.
But I can’t find how to do it.
I have my own email. My email provider said it is a Pop3 account.
I can set it with default outlook configuration. I need to set outlook as my default email client.
Please help me.
Thanks in advance.
