In the past few posts I have talked about application management and how Mirekusoft Install Monitor is more than an uninstaller. In this post I wanted to talk about how uninstallers traditionally work and some of the limitations. In a later post I will talk about how Install Monitor uses an approach that is different from most uninstallers.
How Most Third Party Uninstallers Work
Most third party uninstallers tend to rely on searching predefined locations to remove existing software. There are different ways of doing this scan but essentially it usually requires the program that was uninstalled left behind something that could be used to identify traces of it. Registry cleaners also do something similar. After a scan of the file system and registry the user is presented with a long list of what the uninstaller believes are leftovers that can be removed.
Limitation of Scanning Approach when Uninstalling
This scanning approach however has obvious limitations. Most uninstallers which scan for leftovers now also offer installation monitoring. This process relies on taking snapshots before the installation and comparing to the state after the installation. The user has to start the install with the monitoring program. These programs will sometimes provide a right-click shell extension to make it easier. It can be difficult sometimes to find the executable for instance in the case of updaters. It adds an extra step and some guesswork to the installation. Should a particular install be monitored or not?
Understanding the Downside of Snapshots
Another downside of snapshots is usually they take a lot of time, processor usage, disk activity, and disk space to create. It would not be unusual on a system with a lot of items for a snapshot to take up a minute or more. They in general do not work well with installs that use multiple installers or require reboots.
What happens if bad or unwanted software piggybacks on good software?
It may not be obvious when monitoring should be turned off. Some uninstallers recommend you run and activate the software first.
What if the software does something else that should be monitored?
The snapshot approach increases the probability of spurious activity being caught.
What if another program decides to update itself while the uninstaller is in snapshot mode?
Are there ways to get beyond these limitations?
That will be addressed in a future post.