Acer AR160 F1 - Manual (Page 66)

3 System upgrades 50
Installing a memory module:
Warning! Memory of the identical size, speed, and organization
must be installed in the same colored DIMM slots.
1 Locate the DIMM slot on the mainboard.
2 Install the memory module.
a Align then insert the DIMM into the socket.
b Push the DIMM to the socket until the retaining clips snap
inward.
Note: The DIMM slot is slotted to ensure proper installation. If you
insert a DIMM but it does not fit easily into the socket, you may
have inserted it incorrectly. Reverse the orientation of the DIMM
and insert it again.
3 Observe the post-installation instructions described on page 25.
4 Reconfigure the system memory. See “To reconfigure the system
memory” section on page 51 for more information.