Star Office co-opts emails and web pages

I installed Star Office alongside of Microsoft Office. Now when I’m reading my emails in MS Outlook, and I click on a hyperlink that generates an email message, it tries to send the message from Star Office rather than from Outlook. Similarly, when I am in Outlook and click on a hyperlink to a web page, it tries to display the web page in Star Office rather than Internet Explorer. How do I fix this?