The worry was for nothing: a stick with the hardware version was supplied v4 (very difficult to decipher on the back of the stick, the TP-Link website helps). Without ever having to use the downloaded driver, the WLAN stick was recognized equal to 8.1 under MS Windows and worked immediately.
Conclusion:
Although obsolescence and the WLAN stick works well and provided with acceptable transfer rates under Windows 8.1, hardware version v4.