Oh dear, that was a pretty bad move! Generally speaking, files that are marked as "hidden" in Windows are critical system files that you shouldn't touch.
Without a boot.ini, the boot loader won't be given a list of valid Windows installations to start up, even into Safe Mode. Therefore, your only option now is to boot from the Windows 2000 / XP setup CDROM and choose the option to repair the Windows installation using the recovery console. At the recovery console, type
fixboot (if that doesn't work, it's
fixmbr). This will recreate the boot record and, hopefully, replace your missing boot.ini file.
Let us know how you get on
