Code snippet on How to determine the installed version of BITS - if you need to from your Update App Block (UAB)

http://www.gotdotnet.com/workspaces/messageboard/thread.aspx?id=83c68646-befb-4586-ba9f-fdf1301902f5&threadid=950bf661-b866-4d24-9a1c-67a897fec880 
or,  http://blogs.msdn.com/eugeniop/archive/2004/08/20/217991.aspx