I just tried to install the 64-bit "full installer" version, for
all users with the default options. This is on a PC that hasn't had
3.5 installed before, and doesn't have Visual Studio 2015 installed.
When it got to the step "precompiling standard library" I got an error window pop up saying "python.exe - system error. The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing from your computer. Try reinstalling the program to fix this problem." All there was was an "OK" button. Pressing that told me "Setup was successful" but then "py -3.5 -V" gives me nothing (no error, no version, just returns me to the command prompt). Same result if I do "& 'C:\Program Files\Python 3.5\python.exe' -V".

Python 3.5.0a2 (64-bit) is showing in my "Add/Remove Programs".

This is Windows 7, 64-bit.

"""
Two important notes for Windows users about Python 3.5.0a2:

• If you have previously installed Python 3.5.0a1, you must manually uninstall it before installing Python 3.5.0a2 (bpo-23612).
• If installing Python 3.5.0a2 as a non-privileged user, you may need to escalate to administrator privileges to install an update to your C runtime libraries.
  """

In this case as I said, no previous 3.50a1 installed. and I was doing an "all users" install (which prompted me for elevation, and I said OK)

Same exact issue here. I didn't have a Python 3.5 alpha 1 previously installed, and I tried running the installer normally and also (after uninstalling) with right-click, "Run as administrator".

Both do the same thing for me: pop up a dialog box at the end of installation that says "The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing from your computer..."

I also get the same dialog box when I run "C:\Program Files\Python 3.5\python.exe"

If you look in your AppData\Local\Temp directory then you should find a whole pile of log files. Zipping those up and posting them here or emailing them to me would be great.

It sounds like the CRT update didn't install, since it's supposed to include that file.

Sent via private email as it's a work PC and I didn't check what's logged in there...

Same error on my Windows 7 VM. I have VS 2008 & 2010 installed, but also Python 2.7, 3.3 and 3.4 (all installed twice: 32&64 bits). It's not a fresh Windows :-)

Here is a ZIP of Python 3.5* logs in my Temp directory. I cannot compress the whole directory, it's really huge :-) I have files which are 2 years old in this directory!?

Files:
Python 3.5.0a2 (64-bit)_20150309143635.log
Python 3.5.0a2 (64-bit)20150309143635_001...log
...
Python 3.5.0a2 (64-bit)20150309143635_010...log

Have fun!

I definitely don't want the whole directory, especially from Windows 7 :) (Later versions are better at cleaning up unused files)

I'll take a look once I get to work. Thanks

New changeset 0469af231d22 by Steve Dower in branch 'default':
Issue bpo-23619: Ensure C variable is initialized before using it.
https://hg.python.org/cpython/rev/0469af231d22

Well that was embarrassing, but it's fixed now :)

Larry, would you like me to rebuild the installer with the fix in it?

Yup.

Done, though I may have corrupted alpha 1 in the process :(

New MD5s and sizes:
python-3.5.0a2.exe 9683ecb837ffa2dd321d564042a90d64 28,762,032
python-3.5.0a2-webinstall.exe b717713c58d0fcabf69c4fdc67a2e581 885,256
python-3.5.0a2-amd64.exe 5eb089c6c45913480434388341d3ed4a 29,669,240
python-3.5.0a2-amd64-webinstall.exe 93b883552869c3f936cf6799a6212f04 910,840
python350a2.chm 68007011a878c5cf5f498a3290085066 7,525,910

Any idea how long until the CDN picks up the update?

Scratch that, I screwed up the hg dance (multiple times...). Newer bits coming

Any idea how long until the CDN picks up the update?

curl -X PURGE https://www.python.org/ftp/python/2.7.5/Python-2.7.5.tar.xz

will explicitly tell the CDN to pick up the new binaries. Not sure if that works from anywhere or just from dl-files.iad1.psf.io .

Looks like there'll be some installation errors until the CDN catches up, but the full installer will be fine

MD5s/sizes:

python-3.5.0a2.exe 807a898a6b61696ab9c4257152a939c5 28,762,312
python-3.5.0a2-webinstall.exe dc2cebbb402f117f0590c7d11f662129 885,208
python-3.5.0a2-amd64.exe 91771bce1d8993071b5d766920321ca8 29,669,336
python-3.5.0a2-amd64-webinstall.exe 7b057970b302106304e943da2ccc1ead 910,792
python350a2.chm 68007011a878c5cf5f498a3290085066 7,525,910

Okay, I refreshed the MD5 sums and sizes on the web site, and purged the old files from the CDN.

I downloaded .exe from python.org an hour after Steve said 'done' and install went smoothly -- too smoothly as there was not options dialog as to install location or anything. Fortunately, it did not grab 'python'. New crt was first thing installed.

Start menu/3.5 is missing 'uninstall' and 'doc server' icons.

Tests fail for text_ctypes (multiple), test_distutils (multiple), test_compileall, test_tcl (line 237, in testLoadWithUNC), test_tools, test_zipfile, and test_multiprocessing_spawn froze Command Prompt so I has to close with red [ X ] button.

Thanks for the details Terry.

"Customize" is there for all the options, though I too keep being surprised by just how quickly it gets going when you click one of the other two buttons.

The uninstall icon is probably not going to come back :( I spent some time trying to come up with an approach that would work, but there seems to be no way to know what the command should be. (That said, I just had an idea where we could install the installer and then include a link to that, which would allow it to be uninstalled... hmm...)

I think the ctypes and distutils test failures are expected right now (especially if you don't also have VS 2015 CTP 6 installed), but the others sound new. Do you have the output logged you could post and I'll create issues for them?

Please don't install the installer somewhere, just to add an uninstall icon on the start menu. It's possible to uninstall via "Add/Remove Programs". That should be sufficient.

If there was a *customize* option in addition to *all users* and *me only*, I did not see it. I will look harder for a3. Attached is file with 4 failure messages.

Should have been right there with those two options, looking basically the same. Though it's possible that something about your machine is messing with the sizing - high DPI on Windows 7 is notorious for that, and there are sure to be other potential causes too. Whenever you get a chance to try it again, a screenshot would be nice if it's not there.

There's also some chatter about maybe hiding the all users install behind the Customize button, since it really doesn't gain anything for most people. Then there'd only be two buttons on the front screen, which will make it less likely to be missed.

Thanks for the log. Looks mostly like issues I'd expect when you don't have write permissions for the install directory. Not sure that we have any precedent for dealing with tests that require admin privileges when installed but not in the source tree?

"Not sure that we have any precedent for dealing with tests that require admin privileges when installed but not in the source tree?"

I think we do. With the OS X installer (and, in theory, other Posix-style installs), we have a similar situation where tests are installed without a source tree and I believe they should be expected to be runnable by the user without admin privileges, where necessary, skipping those few test cases that *might* actually need elevated privs. Granted, we currently don't do a lot of systematic testing of tests from installed locations. I do as part of the OS X installer building and testing.

Do those assume that no-admin privs will cause a failure? This is more an issue of "do I have write permissions for the install directory" (which I guess could be its own skip condition...).

Regarding tests trying to write into the install directory tree, I'm pretty sure that there have been fixes added for those but I can't recall off the top of my head specific examples. I think the best approach is to use a temporary, writable directory instead; if that's not practical, then the test case should be skipped. I support fixing any tests that still currently fail due to this.

Migrated the test failures to bpo-23774 and closing this.

I tried to install 3.5.1 32-bit into a fresh virtualbox image from https://dev.windows.com/en-us/microsoft-edge/tools/vms/mac/ (IE 10 on Win 7), and got this same error message. Python will not run, it only shows:

                \---------------------------
                python.exe - System Error
                \---------------------------
                The program can't start because api-ms-win-crt-runtime-l1-1-0.dll is missing from your computer. Try reinstalling the program to fix this problem. 
                \---------------------------
                OK   
                \---------------------------

I tried repairing the installation (with the control panel), which did not help.

Do you have the log files from your %TEMP% directory still? I'll need to see the ones from the original install, not the repair, but you can just bundle them all up.

Create a new issue too - this one is resolved.