A. Because NT command processor CMD.EXE uses '&'
character for separating several commands on the same command line and
PKZIP uses the same character for creating multi-disk archives. Solution
is to enclose '&' in quotes like this:
C:>pkzip "-&" -pr <archive.zip> <files...>.
The other way of getting this to work is to precede the ampersand by a carat (above the number 6 on UK keyboard), as in -ex^&.
There is now a Win32 console (line command) PKZip 2.5 with disk span support. Check http://www.pkware.com
For more information see Knowledge Base article Q130893 (http://support.microsoft.com/support/kb/articles/Q130/8/93.asp)