That's really odd. That looks like the point at which I can click the
button and then print a test page. I've set up ubuntu printing to remote
network attached printers, and to macs for years now with nary a problem.

That said, there are some differences in what you and I have tried to
do, because I don't have any microsoft windows PCs to test with, I
always run linux on the physical machine. and if I ever run microsoft
windows, it's in a virtual machine, so our setups are the inverse of
each other.

Any chance it could be some sort of microft windows firewall or
anti-virus setting? or maybe a problem with running ubuntu in a
virtualbox session...