I have website on Drupal version: 7.26 OS on server is Windows Server 2008 R2 Web server $_SERVER["SERVER_SOFTWARE"]: Microsoft-IIS/7.5 Server API: CGI/FastCGI

Core

PHP Version: 5.3.28
file_uploads: On
post_max_size: 75M
upload_max_filesize: 50M
upload_tmp_dir: C:\inetpub\wwwroot\tmp
memory_limit: 128M
open_basedir: C:\inetpub\wwwroot;C:\inetpub\wwwroot\tmp

When I go to /admin/config/media/file-system

I see error messages:

The directory sites\default\files exists but is not writable and could not be made writable.
The directory tmp exists but is not writable and could not be made writable.

Public file system path: sites\default\files Temporary directory: tmp

I have set permissions on folders

C:\inetpub\wwwroot\tmp : IIS_IUSRS : Full control
C:\inetpub\wwwroot\sites\default\files : IIS_IUSRS : Full control

I am working as Administrator user: C:\Users\Administrator\Downloads>echo %username% Administrator

I can`t change Read Only Attributes for these folders. Every time I do this change and press Apply button and Apply changes to this folder, subfolders and files is checked and press OK button it displays Applying attributes... dialog when it finishing I press OK button on folder properties dialog closing it. When I open Properties dialog once again I see Read-only is checked again. How can I fix it?