Where is my Settings block?
The Settings block has changed to the “Administration” block in Moodle 2.7. It should be on the left side of the course. Here is an example of how blocks look in the default position:
However, it may be "docked". All blocks on either side of your course home page content can be docked. When the white arrow on a block is selected, that block is docked to the left and becomes a tab.
Docked Administration block
When a block is docked and you need to view it’s contents, you can hover over the tab to view options or revert back by selecting the arrow on the tab.
Hovering over a docked block: