When a computer is in safe mode, the Windows Installer Service isn’t started. This can cause some issues as some malware can be removed easier through safe mode or maybe other issues in uninstalling a program force you to use an alternate method. However, if you just try to start the service in safe mode, it fails with an error message (Could not start the Windows Installer service on Local Computer. Error 1084: This service cannot be started in Safe Mode).
Enter SafeMSI.exe, a tiny (and portable) free app that starts up the Windows Installer Service for you. In reality, it’s simply running a registry tweak and starting the service but this makes it a lot easier than editing the registry & starting the service on your own.
You can download the program here