Could you try this if you think the boot device has been inadvertently enabled for VMDirectPath - http://www.vm-help.com/esx40i/VMDirectPath/fix_config_issues.php#disable_boot.
Also on the intial boot screen for ESXi you can press Shift+R to revert to the prior version ESXi that was installed. You would loose all configuration changes since the host was last patched.
sir do you have another tool or process? my IBM x3250 M3 does not boot on CD i already configure the bios setting to boot 1st on cdrom drive.
thanks
rhoks
Have you tried the shift+R option?