Wirelss speed issue-mystery!

[#1]

My daughter's laptop records a wireless speed of 24mbs anywyhere in the house, whether it is next to the wireless router downstairs, next to the desktop in the study upstairs. Also, her laptop records 24mbs when wired with the ethernet cable to the wireless router. However, the desktop in the study only records 4mbs wirelessly. (I can't connect it via ethernet as it's too far away). This suggests a problem with my desktop? Any suggestions as to what the problem might be and how I could reslove it?
Thanks
Bertie and George

[#2]

Could you clarify what you are testing these speeds with, also what adapter type you are using model b g or n, also which operating system.

[#3]

most likely the two machines have different network cards. I've two laptops one with a g standard the other n standard, the g one max's out at 19Mbps and the newer higher spec n card can do my line speed of 51Mbps. It' down the what the network card can handle.

[#4]

If the desktop has a USB dongle for the wireless, consider using a shortish USB extension cable so you can move the card about and get the best possible signal. Even raising it a couple if feet or orientating it slightly differently can make a huge difference.

[#5]

I use a USB Wireless n Adapter on my pc and I use the short usb extension cable that came with it....I had to move it around a bit to find a sweet spot.Even moving it an inch at a time can show a big difference in signal strength...I get a full 5 bar 100% signal having found that sweet spot. 

[#6]

http://www.amazon.co.uk/TP-Link-TL-PA211KIT-200Mbps-Powerline-Ethernet/dp/B004INVKP4
For £30 you get an up to 200Mbps connection to the router.

[#7]

This is the USB Wireless n Adapter I bought about a month ago....it's 300Mbps dual band....meaning you can choose to operate on 2.4GHz or 5GHz....there's less interference on 5GHz but a bit less range.
I'm on 2.4GHz with my Plusnet 582n router...the router is in my bedroom and the wi-fi signal goes through two walls then to the far end of my living room and I get a full 5 bar 100% signal.
It only cost £17 and I'm happy with it. 
http://www.broadbandbuyer.co.uk/Shop/ShopDetail.asp?ProductID=13590

[#8]

Quote from: jelv

http://www.amazon.co.uk/TP-Link-TL-PA211KIT-200Mbps-Powerline-Ethernet/dp/B004INVKP4 For £30 you get an up to 200Mbps connection to the router.

Another benefit of this is that at the remote end you could put a switch (not much more than £5) which would give you several full speed connections if needed.