OWA Setup Help!

Am trying to setup OWA on a Win2000 Server
box that is also acting as a Proxy server.
Have a seperate NT 4.0 SP6a box that is
running Exch 5.5 sp3. IIS 5.0 is installed on
the Win2000 box. When I try to install OWA on
the Win2000 box it says that I do not have
ASP or IIS 4.0 installed. Anyone have any
work arounds or thoughts on this. Company is
really getting anxious to get OWA up and
working as we have several people now on the
road overseas. Any OWA installation help is
appreciated.
Thanks Jeff