Question why un-installing 1 software knocked out 3 other softwares

[jimdagys]

I was experimenting with a certain DVD software player. When I un-installed it, it knocked out (made un-usable) my
FFDShow (couldn't play AVIs with Media Player Classic)
VOBSub (couldn't display subtitles with Media Player Classic)
AAC Decoder (couldn't play AAC files with Media Player Classic)
Fortunately, I keep all the original install files, so that in a few minutes, I re-installed (over the original) the above 3 softwares and the problem was solved. (AAC Decoder I just double clicked "register.bat")
My question is:
1) Why did un-installing the DVD software player cause these problems?
2) Is that the fault of poor programming on the part of the software maker? Or is this situation an unavoidable consequence when one software is un-installed, other software will be knocked out?
3) Based on the above info, what other software on my computer might I expect to be knocked out?

[t0nee1]

jimdagys wrote:

My question is: Why did un-installing the DVD software player cause these problems? Is that the fault of poor programming on the part the software maker? Or is this situation an unavoidable consequence when one software is un-installed, other software will be knocked out?

B/C it wanted to take out(knock-out) as many other apps before defeat/trashed?...

[jagabo]

Run a Directshow filter manager and you'll see there are hundreds of Directshow filters installed on your computer. When you play a video file DirectShow looks through all those filters looking for compatible components to build a filter graph. This is a complicated process that relies on the filters telling DirectShow what they can do and negotiating how to connect their input and output pins to other filters.

On the one hand this makes Windows' A/V system infinitely extensible. You can add a file reader to read new types of video files, add a codec to decode a new type of compression, add a filter that performs video processing. On the other hand any random application might install a filter that conflict with the the ones already installed. For example, the DVD player software you installed may have installed an MPG/VOB file splitter that's incompatible with ffdshow's MPEG 2 decoder and VOBSub.

You should avoid willy nilly installation of video applications and codecs. You will end up with problems like you are experiencing. And one of these days the system will be so screwed up you'll have to reinstall Windows.

[jimdagys]

But I un-installed the DVD software player. So I would think that there wouldn't be any more influence from the DVD player that is un-installed.

[johns0]

I get the same problem when uninstalling other apps i try out,i have to reinstall most of my codecs to get my other apps to work again.Its not wily nily installing,its just a crappy app that takes out certain registry keys.

[El Heggunte]

jimdagys wrote:

But I un-installed the DVD software player. So I would think that there wouldn't be any more influence from the DVD player that is un-installed.

Many (if not most) uninstallers are stupidly-designed applications. And it seems the examples
came from Microsoft themselves. Ideally, an uninstaller should remove all non-shared
componenets, and remove all references to the rejected software in the system registry as well.
But this is not what happened when you tried to uninstall IE 3.02, MS Office 97, and an
old-&&-cräppy MS wannabe photo editor.

[jagabo]

But I un-installed the DVD software player. So I would think that there wouldn't be any more influence from the DVD player that is un-installed.

Uninstallers don't always uninstall everything they installed. And even if the do remove the files they may not remove the entries in the Registry. Or they may not restore the previous Registry settings. For example the DVD player may have installed an MPG splitter and marked it as the preferred MPG splitter. But when it uninstalled it may have deleted its MPG splitter, removed its reference in the Registry, but not restored the previous MPG splitter's preferred status. It's even worse if you install two programs then uninstall one. For example, install A, install B, then uninstall A. Now B may be messed up as well as whatever was on the system before.