How to set up default mail client when clicking on email link?

So, I'm using my sister's old computer and when I go to craigslist or any other site with a link to an email address, her outlook opens up. On my old Toshiba my gmail account opened up. How do I get my gmail account to be the default email account?



Thanks?How to set up default mail client when clicking on email link?
default programs or tools/internet options( on favorites bar)