Since sagemath-9.2 (see ticket #28838), the command sage -sws2rst was resurrected via a new pip-installable package sage-sws2rst. It can be installed in Sage 9.2 using sage -i sage_sws2rst.

Below is an example of usage. First we download a sage worksheet (.sws) prepared for Sage Days 20 at CIRM (Marseille, 2010):

$ wget http://slabbe.org/Sage/2010-perpignan/CIRM_Tutorial_1.sws
$ ls
CIRM_Tutorial_1.sws

We translate the sws worksheet into a ReStructuredText syntax file (.rst) using sage -sws2rst. This creates also a directory of images:

$ sage -sws2rst CIRM_Tutorial_1.sws
Processing CIRM_Tutorial_1.sws
File at CIRM_Tutorial_1.rst
Image directory at CIRM_Tutorial_1_media
$ ls
CIRM_Tutorial_1_media  CIRM_Tutorial_1.rst  CIRM_Tutorial_1.sws

Then, we can check that it works properly by looking at the generated rst file. Alternatively, we can translate it to a basic html file using rst2html:

$ rst2html.py CIRM_Tutorial_1.rst CIRM_Tutorial_1.html
CIRM_Tutorial_1.rst:176: (WARNING/2) Explicit markup ends without a blank line; unexpected unindent.
CIRM_Tutorial_1.rst:334: (WARNING/2) Inline strong start-string without end-string.

As seen above, there are few warnings sometimes because the translation made by sws2rst is not 100% perfect, but most of it is okay:

$ firefox CIRM_Tutorial_1.html

Moreover, one can use the sage -rst2ipynb script (installed with sage -i rst2ipynb + you may need to install pandoc on the system) to translate the rst file obtained above to a Jupyter notebook:

$ sage -rst2ipynb CIRM_Tutorial_1.rst CIRM_Tutorial_1.ipynb

One can check the result:

$ sage -n jupyter

(This answer was copy-pasted from the ReleaseTour of Sage-9.2)

Note that to translate old .sws files to .ipynb, you may also use the export notebook:

$ sage -n -h
[...]
* List available legacy Sage notebooks:

      sage --notebook=export --list

* Export a legacy Sage notebook as a Jupyter notebook:

      sage --notebook=export --ipynb=Output.ipynb admin:10

To be clear, this isn't anything specific to Windows. The .sws worksheets are for the legacy Sage Notebook software, that is largely being supplanted by the Jupyter Notebook which is what the Windows version provides by default.

You can still run the legacy notebook from the command-line by running the "SageMath Shell" and entering

sage -notebook=sagenb

Enter whatever you want for the "admin password" (It's not important; this is just a legacy of its original design to be a multi-user system). Then I think you have to actually "Upload" the sws files into the Notebook server; it doesn't allow you to directly browse the local filesystem.

This will allow you to quickly use those files, but I would suggest trying to convert them to the ipynb format as discussed in this question: https://ask.sagemath.org/question/358...

Convert SageNB (.sws) worksheets to Jupyter (.ipynb) worksheets

There are several ways to go, depending on whether you want to convert SageNB worksheets from your SageNB collection (they live in the .sage folder in your home folder), or .sws files that exist elsewhere in your filesystem.

For a SageNB .sws worksheet located somewhere visible in your file system, you could convert it to reStructuredText (.rst) using sws2rstand then convert the .rst file to a Jupyter .ipynb worksheet with rst-to-ipynb.

Or you could upload it to your SageNB collection, as indicated by @Iguananaut (run sage -n sagenb, upload the .sws files to your SageNB collection), then use the exporter (launch it by running sage -n export in a terminal) which will offer to export all SageNB worksheets in your SageNB collection to Jupyter worksheets.