Sony VGN-A150 VAIO User Guide (primary manual) User Manual page 241

Why doesn't my computer enter Hibernate mode?
You may first need to enable Hibernate mode. Follow these steps:
1.
Click Start on the Windows
2.
Click Performance and Maintenance, and click Power Options. The Power Options Properties window
appears.
3.
Select the Hibernate tab.
4.
Click to check the box next to Enable hibernation.
taskbar, and click Control Panel.
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