HP did indeed buy Compaq about 7 or 8 years ago.
However, I believe that they maintained the Compaq name for some product lines - mainly or only in the home PC and laptop area, I think.
Why do you think that Acer has either the desire or the money to acquire HP?
It was only about 9 months ago that they acquired Gateway (who also acquired Packard Bell), so they are busily digesting that lot!
They are still only 3rd in the world PC manufacturers table - after Dell and the number 1: HP.
SD