Hi and Welcome!
Have you already tried to uninstall the Norton software and see if the problem has gone then?
You can grab a bootable CD or DVD (Linux Live discs like Ubuntu are very useful for that purpose), bott from that, and see if there is the same problem. This would then rule out Issues with your Windows installation.
Most likely, this might be a hardware issue:
Try the drive in another computer if possible.
And while you are at it, carefully check the cables.
A bad PSU could be a reason for these crashes as well btw.