Thanks for the response Koolkat! Oops, my bad; I forgot to attach the 2nd BSoD to that last post. I'll post the other requested things now too.
As for your other questions and advice: It's a personal computer. Check Disk didn't find any errors but I decided to reformat the two drives in question anyway (one drive was from an old XP rig whereas the other was formatted in Win 7 Pro when I assembled this PC). I definitely didn't expect Norton to be a possible cause but I'll test using MSE and run System File Checker after the two drives are done reformatting. I'll rerun Check Disk too.
I really hope it isn't Norton; haven't had any problems up until these two BSoDs.