Try checking the network settings of your adapter. You can do this in the Control Panel. If you're using Custom IPs, replace the base number and adjust the DNS settings. Use the ones from Google:
- DNS #1: 8.8.8.8
- DNS #2: 8.8.4.4
After this procedure, restart the PC and then retry the download. There is also a possibility that the product you're trying to download to lack availability.