Plusnet webspace folders and Shopping cart software

[#1]

Hi all!
Ive recently been playing with my plusnet webspace. However looking via filezilla tonight inside htdocs, there are two new un-deletable folders: 'download' and 'admin', does anyone know their purpose?
Also, i have been trying to demo some shopping cart software, namely 'prestashop' and 'opencart' on my webspace. However i cannot get either launch their installers. They merely show the contents of htdocs... like this: http://www.griogair.plus.com/
Can anyone shed some light on this conundrum?
Thanks,
Griogair

[#2]

Welcome to the Forums.
I dont know anything about the new fangled web, but the simple htdocs can only handle simple HTML, and not PHP, looking down you directory tree, deep down, you have a directory with an ini file and a php file. the reason you are having trouble removing the ones you specified is that they are not empty, but I assume have all the sub folders, moslty empty, of the shop program 
hope that helps (or hinders)

[#3]

hi again, apologies for the late reply. I believe the cart software is fairly php heavy, so there's my answer!
Thanks for your advice pierre