Standard Windows Operating System Security
Microsoft® Windows® 2000 Scripting Guide
In addition to WMI and DCOM-specific security settings, WMI also respects standard operating system settings. For example, suppose someone has set NTFS permissions on a folder that prohibit you from writing to that folder. If you run a WMI script that attempts to copy a file to that folder, the script will fail with an "Access denied" error because you (and therefore WMI, which is impersonating you) do not have write access to the folder. WMI will not override operating system security in any way.
What if you need to copy files to this folder? In that case, you have to either modify the NTFS permissions or run the script under the credentials of a user who is allowed to copy files to the folder.