I used Putty to remote to Linux machine, and when I use
vim to open a file it always delays and display message
PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused. How can I fix it?
You can either set up X forwarding, or give Vim an option not to try to contact the X server (note that it's an uppercase X):
However, usually Vim does not try to connect to an X server unless it believes one is available; somehow your DISPLAY environmental variable is getting set somewhere.