"Failed to add new Steam library folder"

[ᵐ₁₃ ⱠɆGɆNƉ]

I have bought a new computer, with two drives: A SSD-drive (C:) and a regular drive (D:).
I have installed Steam om drive D:, and set drive D: to default for game installation. But some games, such as Civilization V and Team Fortress 2, I want to install om drive C:.
But when I want to set the installation for drive C:, I get the following message:
"Failed to add new Steam library folder".
Someone who can help?

[Dranak]

Please Contact steam support, they have screw something up here, then normal people cant even do that anymore, sure i bet its a security issue or path name or foldername thats the issue here.

then things is not that simple anymore, and that is seen as standard path, then its a steam/OS issue and not user
"#:\Program Files (x86)\Steam"

i dont care what the issue is
"#:\Program Files (x86)\Steamlib"

or
C:\Games\Steam(lib)

It's clear to all experince user, things has been change by system or steam what and why things sometimes work and not.

and no it cant be right to sit and tell people to get "full control" over a simple installation procedur from app itself.

you can TRY run steam.exe in Administrator rights and see if thats the issue here. but i think it just told steam dont have the rights to do it anymore. ( its a steam issue, lack of rights.)


ps.
worst part you can dump it in the root on other driver i did it on my NAS server as test, last time i look into it., ( just for test dont want it there. and it work so this is a path or security issue with steam and sub-dir issue. and the name steam folder also. )

quite simple Dare them to try do it, and i bet they will get same odd error. this has been this way in along time and im sure most say , user mistake , but something dont add up here.

seem to work then you dont use word "Steam" default name folder,

[wuddih]

do not use program files directory on your OS drive for a secondary Steam library.
you also can not use the root of your drive. create a folder on C and use that for the library.