Part of daily organization with a computer should include a couple things. First, tweak old files on a regular basis, like weekly or monthly. Do this by learning how to permanently delete files. Then as you do this, daily task handling will be easier. Daily tasks with your computer can include working off a calendar. Find something you like that's free, like Google or Outlook calendar, and one you can sync with other devices like your smartphone, so that you work off one calendar and don't get messed up. Then handle tasks, logging them on the calendar and deleting them once done.