Guy,
Thanks for taking an interest in this. I do not have Windows. I wrote that off the top of my head! I still think that unetbootin is no panacea for easy installations.
I say that as one of my test machines will not boot from unetbootin.tcz made pendrive. It does boot fine using my HD/USB install program. And yes, in 3.6 I have added a GUI front end to make the program more friendly.
Perhaps my one machine is the exception and unetbootin is helpful for most. I still have a concern about strongly identifying the device, i.e., UUID and/or LABELS.
Not to toot my own horn, but perhaps a better approach would be to use unetbootin for those starting with Windows and no CD. Use it only for first boot. Because Tiny Core's base loads entirely into ram, one can immediately, select control panel, and select HD/USB install. To re-install using our own installation program. Thereby assuring unique device identification and all necessary directories and files needed for successful operation are created properly.
I need someone running Windows to test this theory and follow-up by creating documentation. I will gladly host in in FAQ or it can be directly entered into Wiki.