I received a question in the PCMech Premium area that asked if Windows 7 will have an improved Add/Remove that will completely uninstall programs compared to the way XP does it. My answer was an easy no, and I explained why. In this article I go into detail on that.

First I’ll say programs that leave crap behind is definitely not a Windows-only thing. On the Mac it’s more or less required to have App Zapper. In Linux there’s BleachBit. In other words, no OS is safe from crap left behind by third-party programs.

The question however is: Why does this happen in the first place?

There are three basic answers.

Answer 1: The more stuff the program "hooks" into, the more difficult it will be to uninstall.

In the question I received originally, the cited example was Adobe Reader. This software is notorious for leaving a lot of junk behind because of all the stuff it hooks into.

On install, Reader is a standalone program. But on an "express" install it will hook itself into Internet Explorer, and Firefox and possibly Microsoft Office. That’s a lot of stuff Reader got its claws into, and therefore the more difficult it will be to get out.

Answer 2: Not closing programs before uninstall (error on user’s part).

You know how many programs state, "Please close all your applications before installing [this]." The exact same is correct for uninstalling as well. Some programs are "smart" enough to say, "Hey! You! Close your stuff before uninstalling so I can get out of here safely!" However many programs don’t do this.

Example: Java.

The vast majority of us use Java only in the web browser. If the browser is running while you do your uninstall, chances are high something will screw up.

Answer 3: Crappy code.

If a third-party program installs bad, it will uninstall bad. Crap code is crap code, plain and simple, and no operating system can magically fix that.

Things you can do when things screw up with the uninstall of a program

Install it again to uninstall it again

Although this sounds ridiculous, this does work the vast majority of the time. You install something, decide you don’t like it and go to uninstall it. The uninstall procedure gives an error. Uh-oh. So you run a "cleaner" program to get rid of it. That didn’t work either. Are you now stuck with it for life?


Installing the program again will usually fix whatever problem it had, allowing you to uninstall it properly the second time.

Close all programs first

Close the browser(s). Close your anti-virus temporarily. Close anything else you have open. All of it. Do it whether you feel you need to or not. After that, then uninstall.

Using a cleaner? Reboot after uninstall of a program before running it.

You install a program. That program hooks itself into many things. You uninstall that program. However the OS still thinks you have it installed because of the currently loaded session. So you reboot. On the newly established session, the OS then "knows" it’s completely gone. At that point, then you run the cleaner program and not before.

Does the program use add-ons or plugins?

As great as add-ons/plugins are, they can leave behind a ton of junk. Firefox is a good example of this. The uninstall process does not remove all those add-ons you put in there, nor does it remove any configuration files specifically for those add-ons. You need to first uninstall all that stuff before removing the browser program itself.

Avoid upgrading programs if the versions are too far apart

Let’s say that for whatever reason you’re running an ancient version of OpneOffice, version 1. You see version 3.1 and decide it’s a good idea to upgrade.

Not really.

Were you at OO version 2, then I’d say go ahead with the upgrade. But from version 1, no. Too old. Chances are high something will mess up.

What happens with old versions of software is that the new versions that are significantly ahead release-wise will usually not install "clean", thereby causing problems later.

General rule of thumb: If the program in question is two major releases ahead concerning the version number, you’re better off uninstalling the old, and performing a from-scratch install of the new (unless the program in question is specifically supports an upgrade from something two releases or greater behind).

What’s the worst program you had a hard time getting rid of?

Were you able to uninstall it, or is it still there? Do you think it was your error, or do you recommend people stay away from X program like the plague? Let us know in the comments.