Since you did not provide any more information, here is a method how to replace the HDD.
To complete the sharky25k's reply, here are the part numbers of the original HDDs:
Example of replacement HDD.
It looks like you're new here. If you want to get involved, click one of these buttons!
to get all the benefits
of being a member!
Get social and introduce yourself in our
or learn about our ACE Program
and What's Happening
Acer Community User Agreement.