Wifi Woes

[hc4361]

I'm with Virgin and pay for the 'up to' 60 Mb'. When connected by ethernet this is the constant speed.

Wifi is the problem. My netbook (Windows 7) and tablet (Android Jelly Bean) both manage at least 30 Mbs which I am happy with. My blackberry smartphone is very speedy, too.

It's my desktop. I have it to dual boot W7 and W8.1 and the problem is the same whichever OS I use, and it makes no difference if I use IE, Chrome, Firefox or Opera.

It struggles to reach 10Mbs download, although the upload is excellent at a consistent 3Mbs. Very often its download speed is less than 5Mb.

My Superhub is in the loft, in the same place as the old Virgin modem/router was. My desktop is where it has always been.

The desktop has a Realtek RTL 8191SE 802.11n adapter and the driver is up to date.

Does anything obvious spring to mind as to why I am having this problem?

[hc4361]

I forgot to mention that the wifi icon on the desktop is showing full signal.