IBM ThinkPad X20 Supplementary Manual page 45

8. Replace the memory slot cover over the memory slot, aligning the back
side of the cover first; then tighten the screw.
9. Put the battery pack back in place and turn the computer right side up.
To make sure that the DIMM is installed correctly, do as follows:
1. Turn the computer on.
2. Press the F1 key while the "Press F1 for IBM BIOS Setup Utility" message
is displayed at the lower-left area of the screen.
The IBM BIOS Setup Utility screen appears. The "Installed memory" item
shows the total amount of memory installed in your computer. For
example, if you install a 64-MB DIMM into a computer whose base
memory is 64 MB, the quantity shown in "Installed memory" should be
128 MB.
Install a memory module
Chapter 2. Solving computer problems
35