This document contains known considerations for operating your ThinkPad A21e system (Type 2655).

• Although you can upgrade the hard disk drive (HDD), it is not designed to be removed and reinserted on a regular basis. Repeated and frequent removal, for purposes other than to upgrade for greater capacity, can cause damage to the system. The Ultrabay 2000 HDD adapter is designed to provide this flexibility with a second HDD in the Ultrabay 2000.
• The system must be in hibernation or power-off mode when changing either the main battery or the second battery.