Raspbian Wheezy is no longer on the download page. https://www.raspberrypi.org/downloads/ Jessie is rolled into the latest download for Raspbian. and Wheezy has been removed from the download page. Some hardware functions (temperature, buttons, ir) won't work if you use Wheezy. (Yes, I need to get to updating some of the PiClock software to get this to work). The last version of Wheezy is archived here: https://downloads.raspberrypi.org/raspbian/images/raspbian-2015-05-07/2015-05-05-raspbian-wheezy.zip

This probably won't work on a PI 3. For that, see here: https://www.raspberrypi.org/forums/viewtopic.php?f=91&t=138149