There are some ways for you to change the page title in Magento.
1) CMS page: Go to backend and open CMS > Manage Pages. Select page to edit and you can set title in 'Page Title' field.
2) In frontend and any module, you can use xml file to set new title for your page. The syntax is:
Your new page title
3) If it does not work, now you should look at your block php file. You might easily find this line:
Change the $title to what you want.