I presume laptop ereader refers to the application NOOK for PC or NOOK for Mac. If this is the case you should be able to read your eBooks on both devices.
Check the settings tab in your application and make sure the account information is the same as the account information on your Barnes and Noble account. Aside from that you really haven't given enough information to determine why your eBooks are no longer on your laptop application.
Make sure that there is nothing in the search box (clear the search box) and clicking on the x next to the space
THEN clicking on All Items underneath My Library should make your library appear.
Let me know if this worked for you....