When updating your Python IDE PyCharm to the latest version you might run into an issue on older machines. It looks like PyCharm will helpfully install a 64-bit JRE, but not a 32-bit version, even if you opt to include both 32-bit and 64-bit startup shortcuts.
When trying to start 32-bit PyCharm after such an install you’ll get an error that looks like this:
But hold on. You may not need to go out and search for and install a complete JDK to satisfy PyCharm’s needs. A simple JRE will do and if you happen have an older version of Pycharm already installed on your machine you don’t need to download anything.
On my old Windows XP test VM I found a “jre” directory under “C:\Program Files\JetBrains\PyCharm 4.5.3\”. Copy that directory into the new version’s location (“C:\Program Files\Jet Brains\PyCharm Community Edition 2017.2\” for me) and try again.
It worked. No downloading and no new environment variable.