I previously used wired internet and all as good.  Since I have had ot move my PC and use wifi with the adaptor it is dreadful. It is not the wifi as I am fine on my phone next to the computer,

This is speed test for T2U adapter 

ping 139 ms, download 0.6 mbps, jitter 1297 ms, upload 0.6 mbps

Using the same speed test website this is for Android phone in same position.

ping 13 ms, download 29.2 mbps, jitter 2 ms, upload 5.0 mbps

I have tried two different drivers, uninstalling and reinstalling and the connectivity tool, that does not recognize the adapter.

According to DEVICE I am currently using TP-link Driver version 1030.41.514.2020, date 21/08/2020.

Help gratefully appreciated.

Alan