Sony's official support site explicitly states that there are no available driver downloads for Windows, as the adapter was intended solely for home entertainment hardware.
After searching forums, a user finds that the UWA-BR100 actually uses a chipset (Wi-Fi + Bluetooth 4.0). The trick: use a generic Realtek driver, not Sony’s old one. sony uwa-br100 driver windows 10
Another official software package that includes the driver is the (often shipped with soundbars like the HT-CT150). This manager allows Windows to recognize the dongle as a playback device. Sony's official support site explicitly states that there
In the early 2010s, the Sony UWA-BR100 Go to product viewer dialog for this item. Another official software package that includes the driver
Before diving into drivers, let’s clarify the hardware. The is a USB 2.0 wireless network adapter that supports 802.11 b/g/n (2.4 GHz only). It was originally bundled with select Sony BRAVIA TVs (like the KDL series) and Blu-ray players to enable Wi-Fi connectivity for firmware updates, Netflix, YouTube, and other smart features.
Sony does not provide official Windows 10 drivers for the Go to product viewer dialog for this item.