Okay, so problem not fixed-- do your wife or this friend use any sort of X-Fi sound cards either?

I'm not sure about their issues, but I have an idea about yours. There's reported BSOD STOP-code 0x00000076 "PROCESS_HAS_LOCKED_PAGES" problems when using Creative X-Fi drivers on Windows Vista, specifically when using 4GB of Ram. I suggest you check out this thread to get an understanding on the topic:

http://www.hardforum.com/showthread.php?p=1031500642#post1031500642

IMPORTANT: There is a lot of hate mail in that thread, just unnecessary personal bashings against Vista, please ignore all that and look for the suggestions and solutions posted there instead. I do recommend reading all the pages before you make a decision on what to do next.

Also, I'm NOT saying that this is surely your answer, because I am not an expert in this field, but I would like to help best I can, and that thread may be a good starting point... don't forget to backup drivers before messing with 'em!