SYMPTOM:
When attempting to start the Windows Installer service you are unable to change the service from disabled to manual in order to start it.
Note: This does not work on the hardened vaults.

PROBLEM:
By default Windows Server 2012 comes with this service disabled via a local GPO

SOLUTION:
On a non-hardened vault:
1.   On the server you are attempting installation on, execute Run (Windows Key + R) and enter gpedit.msc.
2.   Navigate to Computer Configuration > Administrative Templates > Windows Components > Windows Installer > Turn off Windows Installer
3.   Double click "Turn off Windows Installer" and set to Disabled and Apply
Once you apply, the Windows Installer service will be set to Manual and you will be able to start it.

On a hardened vault:
In an elevated command prompt on the server, execute the following. (Note: Multiple reboots will be required).

1) Confirm that start is currently set to 0x4 by entering the following command:
reg query HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer /v Start

2) If value is currently 0x4, change it to 0x3 by entering the following command:
reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer /v Start /t REG_DWORD /d 3
Enter "Yes" to confirm the change

3) Verify the value is now set to 0x3
reg query HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer /v Start

4) Reboot

5) You should now be able to start the Windows Installer Service. Complete your installation (including reboot if necessary).

6) Once installation is complete, Stop the Windows Installer Service.

7) Change 0x3 back to 0x4:
reg add HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSIServer /v Start /t REG_DWORD /d 4
Enter "Yes" to confirm the change

8) Reboot