Comment 2 for bug 1645066

there are a few things that the user can do to improve the likelihood of this working, or to diagnose an installation that is not working. I am on Windows 10, using a 32 bit version of Inkscape (.exe package):

1. during the installation of Inkscape, the Python 2.7 install is optional, so one must confirm that it has been chosen, otherwise you may be using an older obsolete version of Python.

2. confirm whether you are using a 32 bit or 64 bit Inkscape version, since they go into different directories.

3. confirm that Python 2.7 is actually present. In my case I execute the command:

C:\Program Files (x86)\Inkscape\python>python
Python 2.7.12 (v2.7.12:d33e0cf91556, Jun 27 2016, 15:19:22) [MSC v.1500 32 bit (Intel)] on win32

which reports the correct version of Python. Note that it is very important that this command must be executed from within the directory C:\Program Files (x86)\Inkscape\python\, otherwise you may get a false result due to other installations of Python.

4. Once you have successfully copied the serial directory into the Python installation, you can confirm the presence of the serial package using the command:

C:\Program Files (x86)\Inkscape\python>python
Python 2.7.12 (v2.7.12:d33e0cf91556, Jun 27 2016, 15:19:22) [MSC v.1500 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> import serial
>>>

If you get no response, that is no error messages, then the 'serial' installation was successful. Then type ctrl-Z to quit python, and try Inkscape instead.

If all these steps succeed and if it still does not work properly, then I would submit a bug report.