Problem with FTP server

I screw up my Server 2000
I deleted users from my server:
IUSR_servername
IWAM_servername
After that Web server and FTP server stop working
I recreate those two users and Web server start working but FTP does not
work. I am getting error message:

An error occurred opening that folder on FTP server. Make sure you have
permission to access that folder.

I did not put any login name and password and also member of for those two
user accounts. I do not know much about server 2000. Server was working fine
until I delete some user accounts. I had none open wireless access and lot
of people use my wireless network to access internet. When I clean up DHCP
server from all those users I also look in user account and delete users
that I did not recognize. This is how
IUSR_servername IWAM_servername get deleted. I would greatly appreciate if
somebody help me fix my ftp server. I can not reinstall Server 2000 because
I do not know how to set it up and person who originally install it is no
longer available.
Thank you