Problems in fully uninstalling Python 2.7 from Windows 7

Question

some months ago, I installed Python 2.7 on my laptop (my os is Windows 7). After, I decided to use Python xy 2.7.3 instead of 'pure' Python; so, as suggested, I removed Python 2.7 and tried to install Python xy 2.7.3. However, when I tried to run the .exe file for installation, a warning window appears telling me that Python 2.7 is already installed on my computer. I tried to install a different version of Python xy (2.6) and everything went fine; however, I'd really prefer to use the latest version of Python xy. Actually, I can't figure out what went wrong whie uninstalling Python 2.7; does someone have any clue? I can tell you that I followed the 'normal' procedure for programm uninstalltion; control panel -> Programs -> Remove Program

Thanks in advance

Stefano

Answer 1

Run regedit, backup and delete the registry keys:

HKEY_LOCAL_MACHINE\Software\Python\

HKEY_CURRENT_USER\Software\Python

My problem occurred when changing from Canopy to Python(x,y). So, also delete all folders that are left behind when uninstalling. https://support.enthought.com/entries/23580651-Uninstalling-Canopy

Answer 2

I also had this issue as well. It was due to third party installs. Even though you have uninstalled python, it leaves all the third party libraries that were installed and I think Python(x,y) just detects the directory.

To fix, uninstall Python 2.7 and then check to see if C:\Python27 still exists. If it does, go ahead and delete and then try installing Python(x,y). That is what worked for me.

Answer 3

I faced this issue:
I tried to uninstall the python and fresh install, reason my pip version issue was not getting resolved.
So I deleted the python folder, removed python from system path, and when I tried to uninstall from "Uninstall a program" in control panel, it showed "Windows installation package" error window and could not clean uninstall.
Solution what i found was: In the "Uninstall a program" select python and click repair. And then uninstall the python, it worked for me. Hope this helps and save some time.
PS: I am pretty new to python, and any help correcting me would be appreciated.

Answer 4

Maybe to put an answer out there.

Uninstalling anything from windows can have multiple side effects residing completly on your specific machine. As to what is common:

-> Python sets itself in your windows path. Here is how to modify your windows path: http://www.computerhope.com/issues/ch000549.htm It means that there is a probability that python is gone but the path entry might not be. That is a guess however -> more information needed

-> Are you sure that everything was removed from your computer? If you already did the normal uninstalling process - try to look up if any python directory is still present.

-> Thirdparty installed? Have you downloaded any libs that are still on your machine.

Besides from that - it could be anything - the more information you give us the more we can say about it.

Maybe this post will help you: How to completely remove Python from a Windows machine?

Answer 5

I had python 2.7.12 and wanted to uninstall it for 2.7.9. I had the same problem as you and to fix it I tried to delete all of the local files and then uninstall however it still gave me the same error. So instead I decided to repair the python 2.7.12 and then uninstall which worked perfectly and completely got rid of the error.

Answer 6

I had python 2.7 installed and enthought canopy. I wanted to switch to python(x,y) to access a full version of the OpenCV library. python(x,y) installation complained about python 2.7 already being installed after: 1)Using windows control panel 2)Removing all lingering python files 3)Removing the windows path as suggested above

Not until I removed all registry entries related to python/enthough did python(x,y) install without issue.

Answer 7

I installed Enthought before. When I wanted to install Python(x,y) instead, I met the problems above.

After I had tried to uninstall Enthought and Python(x,y) from the Control Panel and then restart the PC, the problem still occured the next time I installed Python(x,y).

I solved this problem by:

1. deleting all the relevant files in C:/User/UserName/AppData/ about Python, including the third party softwares like Enthought;
2. deleting the Path in user and system Environment; =====the two steps were failed if I didn't do the third step.=====
3. deleting the register keys as @Daniel said. (include all the relevant keys with the prefix py if you installed the third party software about Python. )

HKEY_LOCAL_MACHINE\Software\Python\

HKEY_CURRENT_USER\Software\Python

Answer 8

Locate that set up file which was used to install Python. Run it and choose repair. If that doesn't solve the problem. Go to c:\Python(x,y) and delete this folder completely by shift+Del.

Run that set up file again and click on "Change" which will ultimately install the Python again. By default in my case option to add path and making that version of Python the default on my system was unchecked which can be figured out by seeing the red cross mark in one of the installation screen. Click on it if you want set up to make it default Python version and also click on the option to indicate you want the path to be added in windows environment variable.

No need to touch registry as previous ones will be overwritten again. In my case it worked. I was getting error like:

Fatal Python error: Py_Initialize: unable to load the file system codec LookupError: no codec search functions registered: can't find encoding

Besides that un-installation was failing from control panel. So above steps solved all of my problem. Hope it helps.

Answer 9

1. I Repaired/Modified to install all the components for the Python version I wanted to uninstall.
2. Once that was done, I clicked on Uninstall/Change and that uninstalled it for good.