Running Server 2019. It's a Primary DC, DNS, and DHCP for my network.

When I go to the control panel and try to access the Disk Management snapin, it tells me:

C:\Windows\system32\mmc.exe
Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.

 If I go to the path directly and run mmc it runs fine.

It also does this for C:\Windows\system32\control.exe when trying to change adapter options.

I've run sfc \scannow and it reported no problems.

 

Solution

Can you validate that the following policy is set to either Enabled or Disabled

Security Settings / Local Policies / Security Options / User Account Control: Admin Approval Mode for the Built-in Administrator account.

There is a known issue with Windows 2019 as soon as you promote the server to a Domain Controller, this policy is reset to "no value". This cause a lot of issues.