Low speeds are quite normal in this village, 0.5Mbps is good. But on top of that I now regularly get upload speeds (0.37Mbps ten minutes ago) faster than download (0.11Mbps) - measured using PC Advisor Speed Test. Windows XP SP3; router and adapter both -n; browser Google Chrome or IE8; TalkTalk broadband (was Tiscali). WiFi connection stated as "135.0Mbps, Strength excellent, Status connected".
Try this, I used it on my Wireless Laptop and it worked wonders, TCP Optimizer click here use the Optimize button on its default settings, You can make a backup of your old settings if you want to restore them later, in the menu