System Python conflict between Anaconda and existing Python installation

Question:

I’ve been going with a basic Python3.4 install that I’ve been installing many modules into for over the past month but have reached a point where pip is coming up short and I’m going to just install the full Anaconda on my system to go deeper into bokeh-server stuff.

I get a popup during the Windows 64bit installer (Anaconda3-2.3.0-Windows-x86_64.exe) saying

A version of Python 3.4 (64-bit) is already at C:Python34 We
recommend that if you want Anaconda registered as your system Python,
you unregister this Python first. If you really know this is what you
want, click OK, otherwise click cancel to continue.
enter image description here

Didn’t find much documentation on this subject, and I’m not really sure how to “unregister” that installation of Python apart from uninstalling it entirely from Windows which I imagine would accomplish such a thing. Is this basically telling me to check how my Python Launcher for Windows is setup after the Anaconda installation? I’m completely unfamiliar with this notion of python system registration? Is that just a round about warning about which python version takes precedence on the system path, or which installation holds the file associations?

Asked By: jxramos

||

Answers:

Here is a link to a script that will unregister a Python installation (if you haven’t come across it already). I personally have not dealt with anything like this. It seems like it should work, but you may have to tinker around with some of the paths in the script to get things to work. The links in @nightuser ‘s post will also probably fix the issue.

Why not just remove your version of Python? You could do a pip freeze > requirements.txt with your current Python and add them to Anaconda, or create an environment with Anaconda using those packages. Anaconda has greatly decreased the amount of time I spend setting things up.

Answered By: wgwz

The solution is simply to uninstall python (for example, run the original python installer and select the uninstall option). The python key in the windows registry will be removed (which is what unregister means in this context).

Answered By: Quaternion

enter image description hereYou have already installed python in your environment, so your system can handle your python code. Anaconda can handle your python code as well. If you install Anaconda and expect use python provided by Anaconda, then your system will confuse about assigning the code job. To avoid this confusion, there is always a path to point out which python you want.
You can ask your OS to find specific python by changing your environment path in windows OS:

By deleting the python path your Python will be invisible. Changing path is more convenient compared with the uninstall.

If you got a python compiling software like Pycharm, things are different. Pycharm may have python3.6 while your system got python 3.5. You need to delete path in those software or uninstall python specified by those software.

Pycharm

Actually, instead of registering the Anaconda as the system python, you can install it first, then specify your Pycharm and system path to the Anaconda python path. Thus, your Pycharm will use python provided by Anaconda and package & virtual environment you need.
I edit this for lots of times because I got Great wall, so I can’t close something pop up in my screen(cause it is Blank). And everything is missing if I refresh. This is annoying.

My system path Anaconda3’s python36

My system path Anaconda3's python36

Add path in Pycharm

Add path in Pycharm

Or you can’t use these packages and Anacon’s virtual Environment

Or you can't use these packages and Anacon's virtual Environment

Answered By: Tina Liu

You are getting that prompt because you have another version already installed the safe way to do this is going to the directory of the existing version and running the uninstaller. Once the previous version is completely uninstalled. You can run the installation as normal it should works!

Answered By: Kirubel Tadesse

Here is a solution which is simple, direct but kind of radical. So check your dependency before doing this.
Considering go to the Control Panel of your Windows and simply uninstall the version of Python which conflicts with the installation of Anaconda. The newly installed Anaconda will easily replace it.

Answered By: Prince Chen