Zencart & PHPBB Forum path problems

Hi,

I am installing Zencart on to my server and need to input the path for my PHPBB forum. Does this mean the physical path or the virtual path?

For example my physical path for Zencart is: e:\domains\e\enchantedrealms.co.uk\user\htdocs

And my Virtual path is https://www.enchantedrealms.co.uk/htdocs/store/

On the server the forum configure file is located in https://www.enchantedrealms.co.uk/htdocs/phpBB3/

And on my computer the forum is located within the Zencart files, in the store file, but I not sure what this would be.

Also, while I am here, granted I haven’t set up Zencart fully yet, the database is running and up to date but I am half way through the installation on the server. However now when you go to https://www.enchantedrealms.co.uk it comes up with the following error:
“Notice: Undefined variable: PHP_SELF in e:\domains\e\enchantedrealms.co.uk\user\htdocs\xampp\lang\en.php on line 252”
what does this mean?

Any help would be much appreciated.

Thanks.
Leanne.

Does anyone know?
Thanks

I think I have figured this out, I have put in the physical path I used to install Zencart then just added to it to locate the phpBB forum and where it is located.