Multiple backups on Norton Ghost 14

I have two internal HDs, C and D. I’ve set up Norton to do a complete drive image on D and then I set up another complete drive image onto my external USB drive. The internal D drive is same size as C so doesn’t hold too many backups. I will however be able to save many months of backups on my USB external drive. Is this a procedure that will work or was I supposed to “offsite copy”  to my USB drive. Is it permissible to set up two different backups of C?? I’m a bit confused and want to be sure I’m safe. I can boot from the SRD and made one as well. When I do driver test it says "packet scheduler miniport - class net - hardware ID ms-pschedmp.  I have no idea what that means.

If one does the offsite copy routine can we restore from this copy in a emergency?

Thanks.

maya