It would help if you told us what motherboard.
For most motherboards there (at least those based on the Phoenix BIOS), there is an option for
Halt on
[*]All Errors
[*]No errors
[*]All, but Diskette
[*]All, but keyboard
[*]All, but Disk/Key
or something similar.
Depending on the make\model it's either under the general menu or the boot menu.