If you installed joomla, wordpress and other script on your domain. via Fantastico and you removed it manually (deleted files and database) because you had some errors on it or for other reasons . and tried to install again using fantastico. However, he was receiving the following error:
You cannot install more than one script in the root directory of a domain.
This error can occur because of the following reasons:
1) Previous installation of script in the root folder (main domain or any addon domain) was removed manually.
2) Fantastico itself hasn’t removed the previous installation properly.
1) Login into your cPanel
2) Go to Filemanager.
3) Now go to .fantasticodata then select the file name installed_in_root.php and remove the following code.
$installed_in_root["yourdomain.com"] = 1;
Removing this will fix the issue and then you will able to install script to the root directory.