Unable to clear cache for all folders

[43rdworld]

We recently had a server crash but were able to restore our site from backups. However, since then, I've been unable to fully clear my cache - whereas prior to the crash, everything was working fine. Some folders clear but not all. I get messages like:

Warning
JCacheStorageFile::_deleteFolder JFolder: :delete: Could not delete folder. Path: C:\inetpub\wwwroot\cache\com_languages
JCacheStorageFile::_deleteFolder JFolder: :delete: Could not delete folder. Path: C:\inetpub\wwwroot\cache\com_modules
JCacheStorageFile::_deleteFolder JFolder: :delete: Could not delete folder. Path: C:\inetpub\wwwroot\cache\com_templates
JCacheStorageFile::_deleteFolder JFolder: :delete: Could not delete folder. Path: C:\inetpub\wwwroot\cache\mod_menu
JCacheStorageFile::_deleteFolder JFolder: :delete: Could not delete folder. Path: C:\inetpub\wwwroot\cache\mod_search
JCacheStorageFile::_deleteFolder JFolder: :delete: Could not delete folder. Path: C:\inetpub\wwwroot\cache\_system
Only some cache group(s) have been cleared.

Error
Error clearing cache group(s): Site > com_languages.
Error clearing cache group(s): Site > com_modules.
Error clearing cache group(s): Site > com_templates.
Error clearing cache group(s): Site > mod_menu.
Error clearing cache group(s): Site > mod_search.
Error clearing cache group(s): Site > _system.

All the folders exist and the contents of the folders correlate with the contents I'm seeing on the Clear Cache screen as to number of files etc.

I'm doing everything locally and have full administrative access to the machine - should I just stop the site and delete the cache files manually and let Joomla rebuild the directories of is there another, better way of resolving this error?

Thanks in advance.

[sovainfo]

Sounds like the NTFS rights are not set properly for IUSR !

[43rdworld]

Everything looks the same permission wise with the IUSR account - special permissions only for the folder but nothing set. Yet it works for some and not for others. User account had Read, Write & Execute and IIS_USRS have only Read & Execute