RaYzHD
You have Norton AV running, please uninstall it using the removal tool here restart the computer and then check that Windows Defender** has automatically been enabled, use the computer as you normally would to see if the computer crashes, post back with an update for us.
** Windows Defender in Windows 8 and 8.1 is an upgraded version that offers the same real time protection as Microsoft Security Essentials, you do not actually need to use a third party AV software unless you specifically want to, not using one does however avoid potential conflicts.
Just a btw, yours is the second such W8 post I have answered today where Norton AV may be the cause.