I have united linux 1.0 and i don't know whether FTP server is installed in it or not. How to find? I used the command 'which ftpd' but that doesn't work. I need your help.

1. How to check if FTP server is installed?
2. How to start FTP server?

both the questions with respect to united linux 1.0

From what I know United linux is based on SuSE (actually SUSE, Turbolinux, Conectiva and SCO) and from what I know a dead project. IMO you would be better upgrading to SuSE since it would contain support for new hardware and the latest security updates. As a side warning using a ftp server on the internet can be a security risk.

I would guess that united would be a similar to SuSE but I don't know if united used yast or something similar. FTP servers are typically run via inetd and I would guess that the ftp server installed is probably proftp. Edit the files in /etc/inetd.d so that the ftp server will run by setting disable = no.
The command to start inetd would be:
/etc/init.d/inetd start