Recently I found on one of my systems that I was unable to access c$ even when using admin credentials. The solution can be found at https://support.microsoft.com/en-us/help/951016/description-of-user-account-control-and-remote-restrictions-in-windows The Fix It For Me feature of the article is no longer supported but the description of the manual fix via regedit works:
- Click Start, click Run, type regedit, and then press ENTER.
- Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System - If the LocalAccountTokenFilterPolicy registry entry does not exist, follow these steps:
- On the Edit menu, point to
New, and then click DWORD Value. - Type
LocalAccountTokenFilterPolicy, and then press ENTER.
- On the Edit menu, point to
- Right-click LocalAccountTokenFilterPolicy, and then click
Modify. - In the Value data box, type
1, and then click OK. - Exit Registry Editor.