A:AnswerThe ASUS USB‑BT500 adapter is compatible with your ASUS desktop running Windows 8.1 64‑bit Home Edition.
https://www.asus.com/networking-iot-servers/adapters/all-series/usb-bt500/techspec/
A:AnswerNo, this Bluetooth adapter only provide wireless connection, it doesn't support wired keyboard and mouse connection even using a USP power hub.
A:AnswerThe ASUS USB-BT500 offers a range of up to 10 meters with classic Bluetooth (BT-BR/EDR) and up to 40 meters in open space using Bluetooth Low Energy (BLE).
https://www.asus.com/networking-iot-servers/adapters/all-series/usb-bt500/techspec/
A:AnswerYes, this Bluetooth adapter will work if your old PC meets the system requirement of this adapter and your printer is a Bluetooth-enabled device.
A:AnswerYes, the ASUS USB-BT500 Bluetooth 5.0 Adapter allows your PC to connect wirelessly to a Bluetooth-enabled home audio receiver, enabling audio streaming from your phone if routed through the PC.