Windows 10 UAC/System Installer

Question

I am running Windows 10 Pro [Build 10240] and upon logging in tonight I find I am unable to install an MSI file as The system administrator has set policies to prevent this installation only, I do not recall doing this, at all.

So I did a little digging and found this post, pretty cool. The best solution on this post was to run the install from an elevated command prompt, so I ran the following command:

msiexec /i example.msi 

This resulted in the same outcome. Using the /a switch also did not help me. So I did more digging and found a "fantastic" Microsoft post here. It applies to Windows 7, so I guess that's why the key does not exist on Windows 10 - the solution was to set DisableMSI with REG_DWORD = 0 in the HKLM\Software\Policies\Microsoft\Windows\Installerdirectory.

So, square 1. Another solution is to set UAC to never notify...isn't this default on a home system? Ran though and double checked it was set to never notify, rebooted, no change.

I wept for hours until I found another option. The next solution I found was to edit the Local Security Policy for Software Restriction Policies. I messed around in here and could not isolate where to add the entry. I added a new hash for %userprofile%\Downloads\ to allow all users to execute file types and ensure MSI was in the list.

I have ensured that my Anti-Virus is not blocking the registry changes, disabled all shields and re-attempted to no luck. I am now performing a full system scan to see if there are any threats on my PC. Long shot, but worth it.

Whilst that is running, I have made a new local account on the PC and ensured it admin rights. I've ran mmc and ensured it in the Local User and Group Administrators group. Once the scan is done I plan on logging out, and attempting to install. I doubt this a user restricted issue but want to rule it out as an issue.

Next I ran gpresult /h report.html and have a quick look to see if I had messed up GPO (I do set local GPO) and all looked well; just my standard disable of gadgets/Cortana etc.

Next I ran sfc.exe /scannow and found no issues here. Frustrated, I went and edited the following values in Local Group Policy:

Computer Configuration > Administrative Templates > Windows Components > Windows Installer with the following:

Install with Elevated privileges set to enable.

Turn off Windows Installer set to disabled.

Same option with User Configuration. The last step is I have redownloaded the MSI and validated it not corrupt (works on Win8 VM). Any assistance would be appreciated.

Answer 1

I rolled back to a previous image, and performed a sfc and found multiple errors. I repaired the install, updated (via Windows Update) and now am able to perform the above mentioned.