Transferring file from raspberry pi to PC

Reading your message, I have the feeling you are doing this:

1. connect to RPi via SSH and get a shell
2. Inside that shell, try to run scp with the desktop PC name/address
3. get the error you describe

If that's correct, then you are mixing things up as scp is to be run from the PC without any regards for the direction of transfer:

PC (scp) ---> (ssh server) RPi

which means you need to have an scp client on the PC, easy to come by under Linux, not that much under Windows command line, but WinSCP is your friend with a nice GUI.

I've discovered many tutorials come up short because they fail to define the environment the test was run. When the environment changes so may the test.

It appears the Pi cannot translate the hostname of your desktop to the required IP address.

Try this test from the Pi

ping <hostname of desktop>

Do you get a response? Let's assume not and work on solution.

try adding .local to the desktop hostname.

<hostname of desktop>.local keeping the command the same except for that change.

This adds dynamic DNS to find the IP address of the hostname of the desktop

ALternate solution

Do you know the IP of your desktop?

Replace the <hostname of desktop> with the IP address, keeping the command the same except for that change.

There are already here great solutions - colporteur is spot on.

But, since you're on windows, there are applications that can do that graphically - like WinSCP . It's very easy to use. You just need to know the IP address of the RPi so you can connect to it.

pooja_14 said:

ssh: Could not resolve hostname desktop-qlv0tg3: Name or service not known

Have you tried using IP addresses instead of host names?

I assume by the yellow header you have been successful. Please don't assume it works everywhere but the chances that it will are improving.

The DDNS (dynamic domain name service) is a fairly new protocol. New in the sense more devices are supporting it. DNS translates URL to IP Addresses for the networks across the whole world. DDNS does the same translation for your little part of the world networks, provided one of the active devices in the network supports it.

It is best practice or a good idea to be familiar with using IP's to perform communication tasks. Using the IP removes the need for any overhead services that might contribute to the problem.

I would also suggest if this is your first foray into ssh (scp is the copy program within the suite) you locate the file /home/<username>/.ssh/known_hosts file. When two host make a connection the initiating hosts stores a hash in this file to identify the hosts it has connected with. You can see this happen on the first connection because you get asked a yes or no question. The next time it makes a connection the host compares what it has with what it receives on the connection. If different it will throw an error and not connect.

Let says for some reason you reload the Operating system on a host. It will send a different hash for a connections. The problem appears often (for me) because I rebuild Pi O/S's a far bit when I am working on a project. I call it flushing the known_hosts file so I don't get the error.

At one point in the ssh protocols life cycle you could look at the contents of known_hosts. For security reason much of the content is now encrypted so all you see now is formatted data. What it is you can't tell.

 pooja_14 few words best solution is to do your dev on a Linux distro like Debian 12  If you don't want to blow up you Windows box -> Linux then install Virtual Box 7.0 its from Oracle (free) and they got it when they bought out Sun Microsystems! 

yes,it didnt work

I assumed your issue was resolved.  What is the current status?

If the problem still exits can you complete a ping test

using the IP address of both the sending and receiving host run the command

ping <IP Address sending host>

ping <IP Address receiving host>

Complete the command first from the sending host and then the same commands from the receiving host.

Record the command an aprox five lines of output.

Your, "yes didn't work" would suggest there is no network conductivity between hosts. Bad network cards, bad connections or bad network are all possible issues.

Since there were quite an amount of good advises, I would add a couple links that offer additional command line options: Ethernet over USB: 
https://www.circuitbasics.com/raspberry-pi-zero-ethernet-gadget/
and serial port over USB:
https://learn.adafruit.com/turning-your-raspberry-pi-zero-into-a-usb-gadget/serial-gadget
Regards,