During a CA Spectrum install on Windows, after the last configuration screen, a UAC error will show in the window noting you do not have proper permissions to run the install.
Spectrum install on Windows
Microsoft has created the following technical guideline to instruct users on how to actually disable UAC. Once you have disabled UAC and rebooted, you will then be able to successfully run the CA Spectrum installation.
This document is for Windows 2012, but also applies to Windows 2016 and Windows 2019
Deactivating UAC in Windows 2008 R2 was possible via running msconfig (for example winkey+r -> msconfig), going to the Tools tab and launching "Change UAC settings".
There, you select "Never notify" to disable UAC.
The same approach is still available in Windows Server 2012, 20016, and 2019 though UAC is still active after you selected "Never notify".
You need to turn off UAC via registry by changing the DWORD "EnableLUA" from 1 to 0 in "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system".
You will get a notification that a reboot is required. On some systems you do not need to reboot. You can log out and log back in and the install will run.
If you look in the installation logs, you may see access is denied errors: