How can I quieten down the fan on my HP 4730s?

For me it was the drivers or compatibility of the ATI (Radeon) graphics card. These laptops have two graphics cards. An on-board one and a more powerful one for gaming etc. What I did, which is crude but works for me, is to disable the ATI card in Control Panel > System > Devices. You don't need the ATI card for any normal PC usage. So if you're not using it turn it off. My fan actually turns off when I'm working on my machine and only runs a little when doing something which makes the machine work harder, lots of browser tabs open for example.

Ted
February 2015

Was it always noisy, or have it became noisy over time?

Make absolutely sure that all vents are free of any obstruction. Any obstruction will reduce air circulation. Less or obstructed air circulation mean that the fan need to work harder, making them noisier.

Make sure that the fan is clean and that all heat sinks are free of any dust. Dust is a good thermal insulator, whitch is very bad on any heat sink. It also prevent the air from circulating freely through the heat sinks.
A dirty fan can get off ballance and off ballanced spinning objects cause noisy vibrations.

When turning the computer on, you have the option of going into the BIOS.
Look if you can slightly underclock the CPU. Underclocking the CPU will reduce the heat generation. Less heat = less work for the fans = less noise.

Electro
January 2014