Windows Vista Access Denied error on C: share when Administrator

This can be caused by Simple File Sharing being enabled on Windows Vista. You can switch this off using the following steps.

1. Launch Windows Explorer.
2. Press the Alt key and from the Tools menu, select "Folder Options...".
3. In the window that appears, select the "View" tab.
4. Scroll to the end of list of options and clear the checkbox "Use Sharing Wizard (Recommended)".
5. Click OK to close the window.
6. Reboot your PC.