This is my neighbour's PC, so bear with me if I'm a bit short on some details.
His problem is …
Sync speed = 6.5 Mbps
Upload speed = 0.9 Mbps
Download speed = only 0.3 Mbps, when using a wireless connection.
As recorded by both Thinkbroadband's speed tester and speedtest.net.
Why do I think it's a Windows problem?
Because testing with two routers, two PCs, Ethernet vs wireless, and two wireless adapters gives these results (numbers rounded for convenient comparison) …
PC1 - Ethernet - Download 6 Mbps, Upload 0.9 Mbps.
PC2 - Ethernet - Download 6 Mbps, Upload 0.9 Mbps.
PC1 - Wireless - Download 6 Mbps, Upload 0.9 Mbps.
PC2 - Wireless PCI Card - Download 0.3 Mbps, Upload 0.9 Mbps.
PC2 - Wireless USB Dongle - Download 0.3 Mbps, Upload 0.9 Mbps.
Tests repeated with two routers show exactly the same results, within a reasonable statistical variation. All wireless tests run close to the router with the devices connecting at 54 Mbps and a full strength signal.
PC1 - Laptop Acer 5738G, 4 GByte memory, Windows 7, built-in wireless (G - 54 Mbps).
PC2 - Desktop Acer (model unknown) - AMD Dual Core @1 GHz, 1 GByte memory, Win XP SP3, PCI wireless card and USB wireless dongle (both G - 54 Mbps, tested separately).
Router 1 - Etec PTI-845G
Router 2 - Dlink DSL-2640R
The ISP is BT Broadband.
So the problem is restricted to wireless only, on PC2 only.
What should we be looking at next to identify the problem?