If it hasn't been done already, I would download the latest driver from D-Link and install it. Uninstal and remove the settings (if asked) for the existing driver first.

The issue may not be related to the dongle. Check firewall and other software that has anti-virus, anti-malware, privacy or security functions. If an anti-virus program is installed, I recommend uninstalling it, checking for internet connectivity (using a safe site) and then reinstalling it. The same goes for other programs that have live internet monitoring capabilities. Make sure that there is only one anti-virus program installed and that there are no conflicts with other products.