Acpi\sny5001 | Driver

And the fan? Within 30 seconds, it spun down. Then stopped completely. Dead silent. It only came back on when the CPU actually heated up—exactly as it should have from day one.

That's when it clicked. The fan wasn't broken. Windows simply didn't know how to control it because the driver was missing. The laptop was running a "safe mode" fan profile: ON all the time. acpi\sny5001 driver

I went to Sony's support site (using the model number from the sticker under the laptop: ). I looked for "Driver - Firmware" and downloaded a file called Sony Firmware Extension Parser Driver (sometimes labeled "Sony Shared Library" or "VAIO Control Center"). And the fan

I went back to Device Manager. The yellow triangle was gone. had moved to "System devices" and was now named Sony Firmware Extension Parser . Dead silent

I installed it. It took 10 seconds. No reboot needed.