first of all go open up WoW then click play. open wow again and click play. using 1 of the WOW programs go on 1 of the chars u want to use. press Esc and go to video options on teh top right there should be a box that says Windowed view or somehting like that.
tick the box then click save/apply/done/what ever it is. now Wow should have a window around it make the window about half way.
now log in with your SAME/OR DIFERENT account and select a diferent char press ESC go to video options tick windowed view make it smaller and there u are now loged in with 2 Chars at the 1 time.
THE BAD PART
it can be very very laggy.
THE good part
can train at same time
can fight together