To show 'POST' and to change the boot order has to be set in the BIOS itself.
Removing the battery will most likaly only result in a reset of date and time, but for sure not anything in the BIOS settings.
Since there are so many brands and versions of BIOS it's impossible to guide you straight towards the correct settings with the info we have got so far.
Since you are able to enter the BIOS, please have a good look for the "show post" message there.
Also, in my experiences, i found out that, even when you have set the primarie boot device towards your CD, in rare occasions it still will boot from the HD. If that is the case try to ONLY select the CD as boot device and leave all other orders blanc/empty.
BTW: if no boottable disk is found in the CD/DVD player oc windows will of course still boot from other devices, so are you sure the disk is bootable?