Anyone know whether if a SEP 11 machine is upgraded to SEP 12 - basic install - does the definitions for SEP 11 remain for SEP 12 or does the SEP 12 download newer updates?
for SEP 12 or does the SEP 12 download newer updates?
yes
It's change because SEP 12 defination folder location has been changed.
Ok, so is there nothing that gets used from SEP 11.
Yes,
When you will upgrade your sep client 11.x to 12.x,SEP 12.x totaly uninstall SEP 11.x client and reinstall SEP 12.x client.
You have asking same question before
https://www-secure.symantec.com/connect/forums/upgrading-sep-11-sep-12-virus-definitions