Boot problem



My problem started about three weeks ago (well maybe more of an annoyance).
everytime i boot the computer up instead of booting up automatic
as it use to, it will stop after it lists the hard drives and cdroms and say …“hit del to resume”…
i hit the delete key and it will continue to boot as normal.
Anyone have an idea why it may have started this all of a sudden??
nothing new was installed, it is the same as it has been.
My only thought is maybe the battery is going dead??

Thanks to all that reply with any thoughts on the matter