Solving install issues with Python 3.4 on Windows

Question

I have recently tried to install Python 3.4 as an alternative installation on my system in an attempt to familiarise myself before migrating code. My main Python installation is 2.7.6.

I tried the 64 bit installer for Windows, but it came up with an error message

There is a problem with this Windows Installer package. A program run as part of the setup did not finish as expected. Contact your support personnel or package vendor.

After this the install is rolled back (from the point shown below):

I have eventually found a solution to this posted below and decided to share in case anyone else was having the same issue.

Answer 1

After some looking online I found (here) that the issue was related to conflicting pip installs (I have a version already installed for Python 2.7 and apparently this is not compatible with the version that ships with Python 3.4.

To get around this issue I simply de-selected pip from the install options shown below and the install went ahead smoothly:

Run installer again and select PIP installation.

If the PIP fails to install with the same error, you may want to check environmental variables using a tool like http://eveditor.com/ which enables to check whether they are valid. If you had another version installed before, you most likely have wrong PYTHONHOME and PYTHONPATH variables. Fix them by setting them to relevant paths. e.g. PYTHONHOME=C:\python27 and PYTHONPATH=c:\python27\Lib

You will then be able to run and install PIP.

Answer 2

I had similar issues with Python 3.4x on Windows 8.1. Even after a successful install, the uninstaller would fail in the same way. Ultimately, "Method 1" at the MS forum solved this for me when I ran Microsoft's (Un)installer Fix It.

Answer 3

Yup, I have already installed another version of python. I have uninstalled them using Program features. But still the same issue persisted because of the folder which was present in my C: drive. After deleting them manually, the installation got completed without errors

Answer 4

I also had the problem that pip couldn't be installed like @ChrisPosser.

So I deselected pip and the installation went fine. afterwards I restarted the setup, chose "change python" and installed pip. now everything worked like expected.

If you have any problems with windows installers I recommend activating the verbose log like this:

msiexec /i python-2.7.10-1.609.2.msi /lv install-python.log

From the logs I could see that it was the pip install, which was not working.

Answer 5

Yes, I faced the same issue, and was working on this for the past one hour. Was trying to uninstall the Python 3.4.1 from the control panel -> uinstall program -> add/remove program, but was facing issues.

This trick worked for me:

Manually deleted the 3.4.1 folder, which was present in my C folders after I installed the 3.4.1

Then I followed these steps:

-> Went to Regedit.exe, checked in both HKEY_CURRENT_USER, HKEY_LOCAL SOFTWARE Folder, and deleted the Python folders there.
-> windows 8 -> Downloads -> 3.4.1 msi setup (Glad I never deleted it)
-> Right clicked on the msi setup and choose the repair option
-> The repair would re install the Python 3.4.1
-> After this, I un-installed the Python 3.4.1
-> Then I deleted the 3.4.1 msi setup.

Rebooted the system, and now, there is no instance of Python 3.4.1 in my system.