turning off Avast

If I want to temporarily turn off Avast antivirus so I can run scandisk. Can I do so by unchecking its boxes in run>msconfig>startup then restart the computer ? I don't want to delete it from my computer.If I click on the Avast icon in system tray I see a boxes that say Pause and Terminate but I don't see one that says reactivate. I don't know what those boxes do so I want to try it as I mentioned above. Thank you