First, uninstall any versions of Flash still remaining on your system.
Next, download the last version of Flash (22.214.171.1241) without the kill switch code using The Wayback Machine. It’s a large file since it includes versions and tools for all platforms
Then, find and install the NPAPI version of the Flash setup file.
Either file should work on Windows
Next, download and install one of the following browsers:
- Basilisk: https://basilisk-browser.org (Windows/Linux)
- Pale Moon: http://www.palemoon.org (Windows/Linux)
- Waterfox: https://www.waterfox.net (Windows/macOS/Linux)
All of these are still regularly updated.
Finally, load your flash based content!
Note: Follow these steps at your own risk! I confirmed that Basilisk, Pale Moon and Waterfox work on Windows 10 with these steps. The browser list may be updated in the future.