Using gems on Windows without dependencies

gem install GEMNAME -f seems to fail on Windows. That is, if you say
no to the dependency, it will refuse to install.

How can I install a gem without its dependnecy? (railsmachine depends
on mongrel_cluster which depends on the binary version of mongrel which
won’t work on Windows. This is all a mistake, because it’ll run fine
with the Win ver. also - but I can’t get gem to install it!)