How to install and uninstall a program in Safe Mode

I’ve never really understood why uninstalling programs in Safe Mode isn’t officially supported in Windows. The main purpose of Safe Mode is to troubleshoot Windows, and what usually causes the trouble? Right, misbehaving programs. This may not even be the fault of the program itself. Windows is a very complex system and sometimes unforeseeable things happen. If an application has been somehow damaged, it might not even be possible to uninstall it. For example, its service could hang immediately after the system boots, or other programs could interfere.

In Safe Mode, Windows has reduced functionality, because only the core components have been loaded. In such an environment it is much easier to get rid of an application that has gone mad. Windows Safe Mode can be entered by pressing the F8 key before Windows boots up.

In order to uninstall a program in Windows, the Windows Installer Service has to be running. If you try to uninstall software in Safe Mode, Windows will just inform you that: “The Windows Installer Service could not be started.” Trying to start the service manually will only get you: “Error 1084: This service cannot be started in Safe Mode.”

The good thing is that it is not really difficult to outsmart Windows Safe Mode. All of the services that are allowed to start in Safe Mode are stored in the registry folder
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\

All you have to do is to add a REG_SZ key with the service name (not the display dame) and the value data “Service” (without quotes). The service name of the Windows Installer Service is MSIService. As such, the REG file that adds the correct key looks like this:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SafeBoot\Minimal\MSIServer]
@="Service"

All you have to do is copy this to a text file, with the extension .reg, and drop the file into your tool box. Anytime you want to uninstall a program in Safe Mode, you just click on the REG file. You have to remove the key manually if you want to disable this feature. However, I think it usually won’t do any harm.

Please note that it is not always possible to uninstall software in Safe Mode because the corresponding installer program requires certain services to be running. In such a case you might just enable these services as well in Safe Mode by adding their service names to the Registry. The Service Name can be found in the service’s properties in the Services snap-in.