Front page question

Good day!

I've got some problems about FP 3.0 for Linux installing.
I run  fp_install.sh
All going good untill step 3, after it I see:

"Step 3.  Upgrading/Installing the extensions"

"Checking for existing web servers to upgrade...
No existing web servers found to upgrade."
######## Is it good? I have my Apache runing this time.

"Note: If you have not installed the root web then you need to do it
now.
Do you want to install a root web (y/n) [Y]?"
####### I press Y
##### How must I understand " root web"  ?
 " Installing the root web...
Server config filename:  "
#######  I enter /usr/local/apache/conf/httpd.conf
##########  Is it right ?
"FrontPage Administrator's user name "
###### I answer  webadmin
"FrontPage Administrator's password:
Re-enter FrontPage Administrator's password:"
########
"Group of this new web:[]"
##### webgroup
"What type of Server is this"
######## apache-fp
######### Then I see
" Installing root web into port 80...
installing server / on port 80
Will chown web to nobody as part of install.
Will chgrp web to webgroup as part of install.
Starting install, port: 80, web: ""
Creating root web
Web already exists: "<Root Web>".
ERROR:  / installation failed.
Hit enter to continue          "

Can you help me what's wrong with my installation ?

Thanks
 Sasha