Sony VGN-A170 - Manual (Page 227)

Why is the sound of my computer's fan so loud?
The computer's fan may be running at a high speed to cool the CPU. By lowering the CPU speed, you also lower the speed
and noise level of the computer's fan. Use the power schemes to lower the CPU speed.
To lower the CPU speed using the power schemes:
1. Click Start on the Windows ® taskbar, and click Control Panel .
2. Click Performance and Maintenance , and click Power Options . The Power Options Properties window
appears.
3. Select Portable/Laptop in the Power schemes box.
4. Click Apply .
5. Click OK .
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