VIM has stopped using my _vimrc and I can't figure out where it is getting set?

"In VIM, type :version, and that'll at least show you the order that the *vimrc files are being loaded.

As for c), the set directory bit determines where VIM puts its swap files. To specify where the acutal backups go, use :set backupdir"

"You can see which vim init file was found first and used by using the variable $MYVIMRC. Just echo it at the command (colon) prompt from within a vim session

:echo $MYVIMRC"