I think it is the basic input..output system
Which is on my Mother Board.
It tells time and date......
I had to press ESCAPE and then ENTER to get pass it.
I could have pressed F12 or one of the other F buttons
but did not know which one.
The problem was the 3volt Cell Battery
Possible gone down to 2 and half volts.
A new Cell Battery has been replaced
The date is not on the cell battery, so never know how old they are, or how long they have been in stock.
Sometimes they only last a year or 10 years.
If it was not replaced the computer would not boot up.
Years ago they were soldered into the Mother Board and difficult to get out.