Leave the computer on until the battery is completely drained. When the battery is completely drained, the computer will shut down.
NOTE: This time will vary, depending on the capacity of the battery installed.
When the computer shuts down, plug in the AC Adapter and charge the battery for at least eight (8) hours.
NOTE: It is recommended to allow the battery to charge overnight.
IMPORTANT: After fully charging the battery, be sure to follow the steps below to re-enable power management.

Re-Enable Power Management
Power on the notebook computer.
After the computer starts completely, go to the directory where SOAOTH-01192100-US.EXE was downloaded and double-click the SOAOTH-01192100-US.EXE file.
At the "Sony® Power Management Settings Utility for Microsoft® Windows® XP" screen, click "Next".
At the "License Agreement" dialog, click "I Agree" to continue with the installation.
NOTE: Several setup boxes may briefly appear during the installation. As the files are installed, these boxes will close automatically.
At the "Power Management Control Setup" screen, select "Restore the Original Setting of Power Management" and then click "Next".
At the "Power Management Control Setup Complete" screen, click "Finish".
Power management and the low battery alarm on your VAIO® notebook have been re-enabled.