Welcome to the forum @Dinu
Is the browser running on the same machine as node red?
What URL are you entering in the browser?
yes , same machine,when i copy http://127.0.0.1:1880/ and paste in browser it shows this
how can i fix this
I recommend watching this playlist: Node-RED Essentials. The videos are done by the developers of node-red. They're nice & short and to the point. You will understand a whole lot more in about 1 hour. A small investment for a lot of gain.
I recommend this because it looks like you are running NR on a Windows machine but you are paths that would be used if you were running NR on a Raspberry Pi.
okay , thank you
In the screenshot you show the last line from node-red is the serial port opened. Then it shows the command prompt again. Did you do something to make it stop running node-red and go back to the command prompt? Node red must be left running in the terminal while you open the browser link.