# When you uninstall a program on Ubuntu, does the software leave any residue?

Computer systems like Windows have tons of software residue that is left when an application is installed and subsequently uninstalled.

Does Ubuntu have the same problem? Would my 5 year old Ubuntu install run the same as the day of install (not counting some of the system upgrades) if I uninstalled all the software I had installed on it over the years?

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for user's configuration files also see askubuntu.com/questions/24201/… –  Takkat Jun 8 '14 at 10:35
I actually think this is really unanswerable - it depends on the program. So will, some will not. So there is no "answer" to this question. –  Michael Durrant Jun 9 '14 at 13:00

Ubuntu/Linux is set up in a differrent way.

Yes, traces are left behind -but- they do not impact the speed of your system.

On Linux libraries sometimes remain on your system. We call them orphans and there is a program called deborphan that removes them. But all you gain is a bit of space on your harddisk. Speed you will not gain. You get more speed by tweaking settings or by disabling services you do not use.

If you want a toolset that includes deborphan install Ubuntu Tweak.

Sometimes programs leave things there on purpose. Those tend to be settings files we manually edited. If you uninstall you have an option "--purge" that removes those while uninstalling; otherwise you are suppose to delete them your self. But again: these just take up space (and for that matter we are talking kilobytes not megabytes) and do not impact on your speed.

2 things related to speed: keep your / partition under 95% full and make sure your system does not need to swap alot. Those 2 are probably 2 main speed related issues.

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When you say 'set up a different way', do you mean this has to do with the UNIX file structure? Would a Macintosh for example be set up in the same way as well? –  letterhead Jun 8 '14 at 14:10
@letterhead well technically I meant Linux versus Windows. Mac is more related to BSD. They do it also not like Windows but a little different than Linux ;) –  Rinzwind Jun 8 '14 at 14:15
There are usually user settings left behind in \$HOME, the so-called dotfiles. They won't impact the speed of the system either, but once you install the program again your personal settings will be remembered. –  barraponto Jun 8 '14 at 15:59
"And that registry is loaded each time". It's funny how Linux fanboys make bashful false assertions about Windows without even knowing anything about it. You can view the registry hives as just another filesystem -data is not read and processed until a program requests it, just like files on a filesystem. Leaving data in the registry is the same as leaving unused files in a Linux system, and leaving system entries in Windows is like leaving init scripts modified when uninstalling a program. Whether residues are left, and their impact on the system, depends on the software, not the OS. –  Panda Pajama Jun 9 '14 at 8:29

In addition to Rinzwind's answer, some program may leave profiles or files containing , for example, keys, passwords, names and things like personal data. Some of packets can ask you to confirm about keeping such files farther or don't keep anymore, some may not ask. It depends on particular application.

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Uninstalling software is conceptually similar in both Windows and Ubuntu: files may get removed and configuration settings may be removed. Whether or not all the files or configuration settings are removed by the uninstall process, is dependent on the software you're uninstalling, not the OS.

Software (in both Windows and Ubuntu) may leave residues for many reasons ranging from simple laziness of the software creator, to keeping user settings for potential reinstallations, to consciously leaving files created by the software (an example would be a word processing software: users would be pretty mad if all the documents created with it were deleted upon uninstallation)

Generally, leaving files and configuration settings is a bit more frowned upon in the Linux world than in the Windows world, but in most cases any files or registry keys that are left are meant to be used only by the program in question. So apart from consuming space on your hard disk, they should not impact system performance and stability. This is true both for Windows and Ubuntu.

However, programs that make system modifications, such as drivers, daemons, system tools, etc., but actually any software that asked you for root access (elevation in Windows) during the installation process, has no technical obligations to remove everything upon uninstallations, and may leave residues that can compromise system performance, stability and security. Once again, this is true for both Windows and Ubuntu.

If you must guarantee that uninstallations won't negatively impact your system, make sure you install only software that doesn't require root access (elevation in Windows). If you will be installing software that requires root access (elevation in Windows), then all guarantees are off, so I would recommend you stick to software publishers that you trust, and hope for the best.

Notice that when I mention Windows, I'm talking about Windows Vista and above, which run on restricted user accounts by default.

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Wonder why I got downvoted... –  Panda Pajama Jun 11 '14 at 3:07
Not sure, maybe for the subjective remarks like: "laziness of the software creator", " leaving files and configuration settings is a bit more frowned upon in the Linux world" but I thought it was an ok answer. –  captainjamie Jun 11 '14 at 8:10