Fix Network Error 0x8007003b in Windows 11 (2023 Updated)

Network error 0x8007003b is an error that occurs when you try to transfer large files over a network on Windows 10. This error may prevent you from copying or moving files from one device to another, and show a message saying "0x8007003B: An unexpected network error occurred". This error can be caused by various factors, such as:

- Insufficient disk space on the destination device. You need to have enough free space on the device where you want to transfer the files. You can check the disk space by right-clicking on the drive and selecting Properties. You can also free up some disk space by deleting unnecessary files, uninstalling unused programs, or using Disk Cleanup or Storage Sense tools.

- Incompatible or outdated network drivers. You need to have the latest and correct drivers for your network devices, such as your network adapter, router, or modem. You can update your network drivers manually by going to the manufacturer's website and downloading the latest drivers for your devices. You can also update your network drivers automatically by using a driver updater tool, such as Driver Easy, that can scan your system and find the best drivers for your devices.

- Corrupted or damaged system files. You need to have healthy and intact system files for your Windows 10 to function properly. You can repair any corrupted or damaged system files by running some commands in Command Prompt or PowerShell, such as sfc /scannow, DISM /Online /Cleanup-Image /RestoreHealth, or chkdsk /f /r. You can also perform a system restore to a previous point when everything was working fine.

- Firewall or antivirus interference. You need to have a secure and reliable firewall and antivirus program to protect your system from malicious attacks. However, sometimes these programs may block or interfere with your network connection and cause errors. You can try disabling your firewall or antivirus temporarily and see if that helps. You can also add an exception or whitelist for the file transfer process in your firewall or antivirus settings.

To fix network error 0x8007003b on Windows 10, you can try these methods:

1. **Restart your network devices**. Sometimes, a simple restart can fix many network issues and errors. You can try restarting your network devices, such as your router, modem, switch, or hub, by unplugging them from the power source and plugging them back in after a few seconds. You can also restart your computer and see if that helps.

2. **Change the file format**. Sometimes, the file format of the files that you want to transfer may not be compatible with the destination device or the network protocol. For example, if you want to transfer a file that is larger than 4 GB to a FAT32 formatted drive, you will get an error because FAT32 does not support files larger than 4 GB. You can try changing the file format of the files by compressing them into a ZIP or RAR archive, splitting them into smaller parts, or converting them into a different format.

3. **Disable SMB signing**. SMB (Server Message Block) is a network protocol that allows file sharing between devices on a network. SMB signing is a security feature that verifies the authenticity of SMB packets and prevents tampering or spoofing attacks. However, SMB signing may also cause some performance issues and errors when transferring large files over a network. You can try disabling SMB signing on your Windows 10 by following these steps:

- Press Windows+R keys together to open the Run dialog box.
- Navigate to Computer Configuration - Windows Settings - Security Settings - Local Policies - Security Options.
- Double-click on Microsoft network client: Digitally sign communications (always) and select Disabled.
- Double-click on Microsoft network server: Digitally sign communications (always) and select Disabled.
- Click OK to save the changes.
- Restart your computer and try transferring the files again.

Note: Disabling SMB signing may reduce the security of your network connection and expose you to potential attacks. You should only do this if you trust your network and devices .