Hi rhummon,
Welcome to Sony Community!
Most likely, this is Windows 10 audio driver issue since the issue started after the upgrade. Your Vaio VGN-FW450J came with Microsoft® Windows® Vista® Premium 64-bit operating system (O.S.). Unfortunately, we do not have Windows 10 drivers for this type of unit. You may still run Windows Update to download the Microsoft (generic) drivers but if the issue persists, we suggest going back to the previous version of Windows O.S.
I hope this helps.
Regards,
Vincent
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