When you log-in to Diablo with a Wifi or iMac connection, you might receive error 3003. It can happen due to several reasons including incorrect game configurations to problems establishing network connections.
Disable Firewall & Antivirus
- Disable Secondary Log-On Service
- Change Catalyst Control Panel Settings
- Scan Registry Settings
- Disable 3GB Switch
- Enable DisableTrilinearFiltering Setting
- Disable Firewall & Antivirus
- Change Display Setting
Disable Secondary Log-On Service
A computer with Secondary Log On Service disabled can show this error. Battle.Net error 3003 fix is to enable this service as given under:
- Click Start, select Run. Type Services.msc and press ENTER.
- Right click Secondary Log-On Service. Select Properties.
- Select Startup Type => Automatic.
- Click OK button.
Change Catalyst Control Panel Settings
If you are experiencing Battle.Net error 3003 with AMD Graphics Card then change its 3D Graphics Settings as shown below:
- Right click your desktop, select Properties.
- Click Catalyst Control Panel link.
- Click Graphics Settings | 3D | More Settings.
- If the following box is already checked then uncheck it. However if it is already unchecked then check it:
- Support DXT Texture Formats
- Click Apply | Apply.
Diablo can show error if some of its settings can’t be retrieved from its registry entries. Scan all registry hives using a good registry cleaner software and fix all errors found.
Disable 3GB Switch
Using Command Prompt disable the 3GB Swtich as Battle.Net error 3003 fix. Here’s how:
- Click Start, point to All Programs | Accessories.
- Right click Command Prompt.
- Select Run as Administrator.
- Type the following command and press ENTER: Bcdedit /deletevalue IncreaseUserVa
- Restart the computer for the changes to take effects.
Enable DisableTrilinearFiltering Setting
You can make changes to the game settings as I have shown below:
- Open My Computer, double click the drive where Diablo is installed. For example: C:\ drive.
- Press F3 to go with Search feature. Type d3Prefs.txt and press ENTER.
- Press Ctrl + F. Search for DisableTrilinearFiltering. Change its value from 0 to 1.
- Click File | Save.
A network connection could not be made to Battle.net servers due to your antivirus or firewall rules. Battle.Net error 3003 fix is to disable both of them and run it again.
- Click Start, type Windows Firewall with Advanced Security.
- Press ENTER.
- Right click it from the right side panel, select Properties.
- Make Firewall Status as Off.
- Click Apply | OK.
- Now right click your antivirus icon in the notification area, select Disable | Disable until next reboot.
Change Display Setting
Change your monitor settings so that it will show smaller text rather than medium sized text. Open Display settings:
- Right click your desktop, select Personalize.
- Click Display under See Also category at the left hand side on the bottom of your screen.
- Select Smaller option, click Apply and then close the window.