Most commonly, your switch or router is only capable of 10/100 speeds.
Check Google for the router's specifications ( dlink DES1000A switch specs)
New switches are pretty inexpensive and the easiest fix.
You're looking for 10/100/1000 routers or 10/100/1000 switches
...
If the router is rated for 10/100/1000, then on the router or switch are all the lights Green?
If any lights are amber, that means that specific connection is not running at top speed for that router:
The problem is either the network cable ( Here's an Monoprice link for network CAT 5e or CAT 6 patch network cables )
or the computer's network adapter (NIC) is old and only capable of transmitting speed at 100Mbs (125,000 Bytes per second). If so, it's probably on an older computer and there's no easy upgrade.
