Fix PuTTy Fatal Error, Network error on Windows computers

PuTTY is a free and open-source terminal emulator. The software helps us to configure routers, switches, and other networking devices via the command line. It supports many network protocols, including SCP, SSH, Telnet, rlogin, and raw socket connection. However, a lot of users are reporting seeing PuTTy Fatal Error while trying to make the connection between devices. In this article, we will know the causes of this error and see what we can do if our computer says Network Error and the accompanying message could vary as follows:

PuTTy Fatal Error, Network Error

• Software caused connection abort
• Connection timed out
• Connection refused

Fix PuTTy Fatal Error, Network error on Windows computers

If you encounter PuTTy Fatal Error, Network error, Software caused connection abort or Connection timed out or was refused on Windows 11/10, then follow the solutions mentioned below to resolve the issue:

1. Check the Internet connection
2. Make sure the port number and protocol are correct.
3. Check if the SSH connection is enabled.
4. Disable Firewall and Anti-virus temporarily
5. Run a CLI Command
6. Contact IT manager

Let’s get started.

1] Check the Internet connection

Sometimes basic tips can be the root cause of the issue and as the error code is related to the Internet connection, we’ll suggest you make sure that the Internet is stable, and cables are connected properly both to the PC and the router. First of all, check the network speed using one of the free Internet speed testers. In case the speed is slow, we should restart the router once, and lastly, if rebooting your router was of no help, then contact your ISP.

2] Make sure the port number and protocol are correct

The error code indicates that the server denied the network connection attempt PuTTY made to it, due to which PuTTy does not have access to the server. This is probably due to incorrect protocol and port number; therefore, it is advisable to make sure the port number and protocol (SSH, Telnet, or Rlogin) we are using are correct while accessing any device. However, one more thing to Keep in mind is that only a system administrator who has full control can resolve the error by restarting stopped telnet and SSH services. So, if we are a part of an organization, contact the administrator and ask them for the correct details.

3] Check if the SSH connection is enabled

It has been seen that even after the user had made sure that the port and protocol were correct, they were still unable to access the device. Usually, this issue occurs due to disabled SSH on the device. If it is already enabled, then we can see the next solutions; however, if it’s disabled, then we can resolve the issue by enabling this protocol on the device, and to do the same, follow the steps prescribed below.

• Press Windows + I key to open the Setting app.
• Click on the Apps option here.
• Click on Optional features.
• Click on View feature next to Add an optional feature.
• Now we can enable SSH from there.

Finally, see if the issue is resolved after enabling the SSH feature on the computer and if the problem continues to persist, see the next solution.

4] Disable Firewall and anti-virus temporarily

We know how important antivirus or Windows Security firewall is for our computers, both utilities can help our computers to work smoothly and safely from malware and viruses. A lot of time, anti-virus or the Windows Security firewall feature blocks some of the incoming connections resulting in the error in question. Now in this scenario, we need to turn off the firewall and anti-virus temporarily and then check if that can resolve the connection refused error.

To turn off the Windows firewall, follow the prescribed steps.

• Press Windows + I key to open the Setting option.
• On the left side of the screen, click on Privacy & security option.
• Now, click on the Windows Security option there and then on Open Windows Security.
• Click on Firewall & network protection option and select Public Network.
• Under the Microsoft Defender Firewall, click on the toggle-off button.

Follow the given steps to disable the anti-virus on the Windows computer.

• Press the Windows key and type Setting in the search bar.
• On the left side of the screen, click on Privacy & security option.
• Now, click on the Windows Security option there and then click on Open Windows Security.
• Click on Virus & threat protection option.
• Click on Manage Setting under Virus & threat protection.
• Under the Real-time protection option, turn off the toggle.

If you use a 3rd-party security software, you will need to disable it too.

Hopefully, after disabling the anti-virus and firewall, the said error issue will be resolved.

5] Run a CLI Command

If there is some misconfiguration in the login process, there is a high chance that we can’t connect to ResberryPie, in that case, we need to execute the following command.

$ sudo rm /etc/ssh/ssh_host_* && sudo dpkg-reconfigure openssh-server

We can try logging in using this command and our issue will be resolved.

6] Contact the IT manager

The error in question can be due to a lack of access permission for the device, in such scenarios, we should contact our organization’s IT manager. We can also contact them if none of the solutions worked or if you don’t want to do all these steps.

Hopefully, you can resolve the issue using the solutions mentioned in this post.

Read: Best PuTTy alternative for SSH Clients for Windows computers.