Hi scraper,
Welcome to Sony Community!
How did you upgrade the operating system of your Vaio to Windows 8.1? You may isolate the issue by following these suggestions:
- Power cycle - Turn OFF the laptop and remove the battery and all peripherals -> Press and hold the power button for 5 seconds.
- Run Vaio Update and Windows Update to download and install the necessary drivers and software for your laptop.
- You may also download and install the drivers manually from eSupport website: https://esupport.sony.com/US/p/model-home.pl?mdl=SVF15N17CXB&template_id=1®ion_id=1&tab=download#/downloadTab.
Regards,
Vincent
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