Can you control the boot process with a boot manager? On my desktop and my
netbook, pressing ESC gives a boot manager that allows me to choose which
drive to boot from. It would try boot from the other drive in case grub was
written there. If not, it is likely that it did not install properly.

You can load the Live CD and try to re-write grub. Here is how to do that:
https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows

This should give you a boot menu that will allow you to get back into
Windows. However, if the installation of Ubuntu is not complete it may still
not boot and you will have to re-install Ubuntu.