Basic Setup Troubleshooting

Technical Support

This thread is designed to help you troubleshoot and resolve installation, patching and connection related type issues. We recommend taking all the steps below before creating a post or contacting Technical Support.

Additionally, we recommend checking out our Known Issues sticky (Coming Soon) to make sure you are not running into an issue that has already been reported.

1. Downloading
2. Installing/Patching
3. Connecting
Downloading/ Blizzard Downloader Troubleshooting

Power Cycle Your Modem and Router

Many common file transfer issues can be solved by resetting the connection on your modem and router. Visit our Connection Troubleshooting page for detailed instructions on how to power cycle your modem and router.

Firewall Configuration

A firewall is a program or device that filters internet traffic ports. There are two types of firewalls, software and hardware, that can prevent can prevent the Blizzard Downloader from working correctly if they are not properly configured.
  • Software firewalls usually work by filtering or blocking information to individual programs. Software firewalls are oftentimes integrated with antivirus software.
  • Hardware firewalls work by filtering traffic before it ever reaches your computer. Hardware firewalls are usually integrated within your router.

Visit our Router Configuration page for steps on properly configuring your firewalls.

Disable the Peer-to-Peer Protocol

Some Internet Service Providers (ISPs) restrict or block peer-to-peer traffic. Disabling peer-to-peer may increase your download performance. Additionally, older or faulty network equipment may not be able to handle the number of connections that the peer-to-peer protocol attempts to create.

To disable Peer-to-Peer:

- Click the View menu.
- Select Preferences.
- Uncheck the box labeled Enable Peer-to-Peer Transfer.
- Click OK.

Disable Proxy Settings

Check to see if your computer is configured to use a proxy server. An internet proxy is an intermediate computer server that sits between an end user and the internet. It is usually used to filter or redirect normal traffic requests. Most home internet users should not be configured to use a proxy server.
To Remove Proxy Settings:

- Click Start
- Click Control Panel
- Click Internet Options (This might be under Network and Internet)
- Click on the Connections tab
- Click LAN Settings
- Uncheck Use a Proxy Server for your LAN
- If Use a Proxy Server for your LAN is already unchecked, try to toggle “Automatically detect settings”. If it is checked, uncheck it. If it is not checked, check it.
- Click OK.

Network Card Driver Updates

Some connection and network issues can be resolved by updating your network card drivers. These drivers can are usually located on your computer manufacturer's website. For a list of common computer manufacturers and network card support sites, please visit this page.

Run as administrator

Make sure you are logged on an administrator account on your computer when installing or patching the game. If the game is not installed using an administrator account, computer permissions can prevent the installation or patch from completing.

Note: We cannot support the game on a non-administrator account.

When running the installer or patch, we recommend opening using the ‘Run as administrator’ feature.
  • Right-Click the Diablo III Installer or Diablo III Launcher icon and select “Run as Administrator”.

Security Software

Security software (Norton, McAfee, ZoneAlarm) is designed to protect your computer from perceived threats. Unfortunately, many security programs are not game-friendly and will frequently perceive a game installation or update as a threat and shut it down.

Disabling or temporarily uninstalling these programs will often permit the Diablo III installation, or in some cases patches, to complete successfully. However, be advised that some security programs will continue to partially run even when they are disabled.

If you are not comfortable modifying your security software settings, we recommend contacting the software publisher for assistance.

Background Applications

The other programs running on your computer could be interfering with Diablo III's installation or patching. We recommended running in Selective Startup mode when attempting to install or patch, since background applications can interfere significantly with these operations.

You can find more information and detailed instructions for this mode on the Closing Background Applications page.

Hard Drive errors and Fragmentation

A few bad sectors on your hard drive or a high amount of data fragmentation can result in installation or patching errors. To fix these, follow the instructions on our Running Scandisk and Defrag page.

Remove Viruses and Spyware

There may be malware on your computer that is interfering with the installation/Patching process. To deal with this possibility, we recommend scanning your hard drive with game-friendly security programs such as Microsoft Security Essentials, Malwarebytes, Avast!, or Kaspersky.

Memory (RAM)

Lastly, memory (RAM) issues can interfere with the game installation/patching. We recommend running memory scan utilities such as the Memtest86. Run the extended test suite option, as mild errors on your memory sticks will often not be uncovered with shorter scans.

Power Cycle the Modem and Router

A remarkable number of issues can be caused by "jams" within the network cache. Simply resetting the connection to your ISP by powercycling your modem and router can resolve these.

Reconfigure Firewall and Router Settings

If you are using a firewall or router, you may need to manually set up your system to allow access to the game server. Your firewall and/or router will need to allow unrestricted communications on ports 80, 1119, and 6881 - 6999.

Update Your Network Hardware

Old firmware on your modem and router along with old drivers on your network card can cause issues when your network needs to deal with complex game connections. The manufacturer's website for your hardware should have firmware/driver downloads available, as well as instructions on how to apply firmware updates.

Resolve Conflicts with Security Programs and Other Third-Party Programs

Any program on your computer which monitors or uses your Internet connection has the potential to be interfering with Diablo III. Security programs may mistake Diablo III network traffic as being malicious and shut it down, and other Internet reliant software such as chat and download programs (torrents) may end up fighting over the same bandwidth and network ports.

Try closing background applications and see if Diablo III becomes stable. Be advised that most security software will continue to run in a limited manner even when turned off and may require full uninstallation to truly troubleshoot. When in doubt, contact the manufacturer of your security programs for assistance in configuring them to not interfere with Diablo III.

If you have tried all the steps above and are still experiencing issues with the game, create a thread with a description of the issue you are experiencing and what steps you have already tried.

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