The PDF Architect uninstaller does not clean up properly.
Here is how you remove PDF Architect Manger service.
Open Task Manager using Ctrl+Esc
Find the Services tab
Find the PDF Architect Manager to get the full name, fx "PDF Architect 5 Manager"
Run Command Prompt, Run as Administrator.
Uninstall the service using sc delete "Full name of service". In my case
sc delete "PDF Architect 5 Manager"
Ctrl+Esc to open Task Manager. Find the services tab. Find the name of the PDF Architect Manager installed on your system.
Run Command Prompt from the start menu by right clicking and select Run As Administrator
Delete the service using the name found under Services.