I have "Europe Dell Wireless 802.11g/n + Bluetooth v3.0+H S Card". I have reinstalled Windows 10 on my new Hard disk drive and I can see the wireless driver is "Broadcom 802.11n Network Adapter". The driver version is 18.104.22.1686.
I can see that my wireless speed varies from 30 MBPS to 1 MBPS. I have got my work laptop IBM Lenovo and when I check the wireless speed there, it is consistently at 48-50 MBPS. I have BT HUB4 smart wireless router which automatically uses best channel and I can see it is presently channel 1.
It seems to me the problem with either wireless card or wireless driver. On my old HDD I had Dell Wireless driver and I had exactly same problem. So it looks that the wireless card is not up to the job.
I have Dell Inspiron 15 N5050 laptop which is out of warranty.
If you know any idea which can resolve the fluctuation of the wifi speed please let me know.