Not sure with out looking too much into it, but in that case I think you
will have to turn off simple file sharing, this enables you to modify the
NTFS permissions. you will then need to make sure that that folder has:
Users - Full control.
To modify NTFS permissions:
In Explorer click Tools, Folder Options.
Click the View tab.
Remove the tick on "Use simple file sharing), click OK
Then...
Click the file/folder you want to modify the permissions on.
Click the File menu, Properties, Security tab.
Select Users, then click Full Control Allow