When installing by .msi a registry key is created below with a unique GUID for the app.
removing keys from here will remove the app from the control panel but windows will still think its installed which could cause issues when installing the same app with a higher version. This is because Windows copies the .msi into ”C:\Windows\Installer” (Renamed Randomly). You can find out which of these .msi files relates to the app by checking this registry key:
HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Installer\UserData\[InternalUserId]\Products\[some random guid-like sequence of chars identifying to windows your installation]\InstallProperties