I've just upgraded from Virgin 30Mb to Virgin 100Mb. When speed testing my laptop (5yr old, win Vista) I get around 90Mb but when testing my desktop (3yr old, win 7 64bit) I get 60Mb. These results are using the same wired connection, literally unplugging one and plugging in the other. I've replaced the Ethernet card and it hasn't made any difference, turned off the firewall & anti-virus, updated the bios on the mobo, updated all the Ethernet drivers, still no-joy. It's worth saying that the differential between the two machines is always constant, if I get 80 on the laptop it will be 50 on the desktop. Its always 30Mbps behind, something is pulling it down and I don't know what. The upload speed is also slower, 16Mbps on the laptop, 10Mbps on the desktop. I'm close to launching the pc out of the window! Please help.
What browser are you using for the test? Same on both machines? If IE on the desktop, try using IE (No Add-Ons) from Start > Accessories > System Tools. Let us know ...