Locate the category and download the driver (usually listed as Broadcom). Installation Steps
Select the Windows 7 (32-bit or 64-bit) version that matches your system type.
Remember: this laptop is over a decade old. While Windows 7 remains usable, the best long-term solution for stable Bluetooth is either an external dongle or a lightweight Linux distribution (which supports legacy Bluetooth perfectly).
Furthermore, the Aspire 4730Z series utilized different Bluetooth chipsets depending on the specific batch of manufacturing. Your specific laptop might have a Broadcom chip, an Atheros chip, or even a Foxconn module. There is no "one size fits all" driver. Installing the wrong driver often results in the device not being recognized at all. This is why a targeted approach is necessary.