This is a common problem, if you maxing out your bandwidth for an extended period of time, you connection will be dropped. As I recall, it has something to do with the same system that detects your actual connection speed to begin with.
You do not necessarily have to reset the router to get your connection running again when this happens. If you go to Control Panel, Network Connections, right click and Disable your local area connection, and then enable it again. Alternatives would be to unplug your ethernet cable on the router, and connect it to an alternative port. I suspect an ipconfig /renew command would also do the trick.
Downloading a single file alone would not cause this issue, however if you are running something else in the background, especially p2p software will most certainly cause your problems. If you are not running anything in the background, then please can you run through PCHF Prework on my signature to make sure it's not malware.
For PC's that have problems when determining it's connection speed, perform the following actions:
- Go to Control Panel, Network Settings and right click on your local area connection, followed by Properties. - Click on the Configure, followed by Advanced tab.
- Under the catigory of "speed/duplex settings", change this option to the speed that is appropriate for your network connection, often 100 Full Duplex.