IBM NETVISTA X40 6643 - Manual (Page 86)

7. Replace the covers, and plug in the power cord.
Note: When the computer is turned on for the first time after battery
replacement, an error message might be displayed. This is normal
after the battery is replaced.
8. Turn on the computer and all attached devices.
9. Use the Configuration/Setup Utility program to set the date and time and
any passwords.
10. Dispose of the old battery as required by local ordinances or regulations.
70 User Guide