There could be a multitude of reasons for the speed difference kingpin.
For a start, IE is slow and clunky, only use it in emergencies.
You may also have some background apps that are slowing you down.
Have you checked your upload speed/volume.
"netspeedmonitor" is a free and tiny app to check out how much data goes up and down
If something wants to upload, and your trying to download, then you will have no chance.
Do remember that your desktop is running win 7, "Is it trying to download a sheet load of updates"?
Win 7 is heaps better than any win 8 version.
good luck
