Mozilla Firefox

To enable cookies in Mozilla Firefox 3.x for Windows:

  1. Click Tools > Options.
  2. Click Privacy in the top panel.
  3. Set "Firefox will:" to Use custom settings for history.
  4. Check the box next to "Accept cookies from sites" to enable cookies.
  5. Click OK.

To enable cookies in Mozilla Firefox 2.x for Windows:

  1. Click Tools > Options.
  2. Click Privacy in the top panel.
  3. Select the checkbox labeled "Accept cookies from sites."
  4. Click OK.

To enable cookies in Mozilla Firefox for Mac:

  1. Go to the Firefox drop-down menu.
  2. Select Preferences.
  3. Click Privacy.
  4. Set "Firefox will:" to Use custom settings for history.
  5. Check the box next to "Accept cookies from sites" to enable cookies.
  6. Click OK.

These guides where taken from Google