Blizzard Downloader Problems: (PC)

If you have begun the Blizzard Downloader and are experiencing very slow transfer rates, we ask first and foremost that you be patient. The nature of the transfer method is that it takes a few moments to make the connections necessary for the transfer. If you are still experiencing extremely slow downloads after 10-15 minutes or if you are not able to make a connection with the downloader, please try the steps below.

1. Closing background applications: You can visit our Closing Background Applications page for instructions on closing all unneeded processes, then try to restart the downloader. If you continue to experience poor download speed after several minutes, then proceed to the next step.

2. Firewalls: If you have a firewall, be sure that it is set up to allow for incoming connections on ports 3724, 6112, and 6881-6999 for TCP (also called TCP/IP). More information on how to open ports for some popular firewalls can be found on our Networking Help page under the Advanced Networking section. If your firewall is not listed there or you need more help, please refer to your firewall documentation or contact the manufacturer.

Important note: Please be aware that, contrary to what one might expect, many popular firewalls will become very restrictive to traffic when disabled. Please be sure any firewalls you have installed are configured correctly and enabled in order to use the downloader effectively.

3. Routers:

- Be sure that the router configuration has ports 3724, 6112, and 6881-6999 forwarded to your computer, and only your computer. Having the same port forwarded to more than one computer connected to the router can cause a conflict, which may result in slow download speeds.
- Be sure that no computers are in the DMZ (demilitarized zone). If a computer is set up to be in the DMZ, then there may be a conflict, which may cause slow download speeds.
- Be sure that any other computers on the network are not running any programs that utilize large amounts of bandwidth. Remember that a router simply lets all the computers connected share the connection. It does not increase the bandwidth of the connection!

4. Adware/spyware/virus Scan: Adware, spyware or a virus on your system may also cause these symptoms. Be sure to run full scans of your system with the latest definitions for your malware programs. If you need more information regarding where to get a virus scanner, please visit our Computer Security Page.

5. Update network card Drivers: If you have any issues with the download client, we strongly recommend that you make sure you are running the latest drivers for your network card. Many people report that updating their drivers solves their particular issue.

6. Contact Technical Support: If your problem persists, please contact Technical Support for a possible solution.