HP nc6140 - Notebook PC Manual page 10

You can disable hibernation. However, if hibernation is disabled
and the system reaches a low-battery condition, the system will
not automatically save your work while power is on or when
standby has been initiated.
Use Power Options in Microsoft® Windows® Control Panel to
reenable hibernation:
»
Select Start > Control Panel > Performance and
Maintenance > Power Options > Hibernate tab.
Be sure that the Enable hibernation check box is selected.
To set the time interval after which the system initiates
hibernation:
1. Select Start > Control Panel > Performance and
Maintenance > Power Options > Power Schemes tab.
2. Click one of the intervals in the System hibernates list.
Power
Standby and hibernation
3–3