After some testing, I’m pretty sure the software you’ve currently got loaded on your Pi (actually an experimental OS dubbed PiratePython aimed at providing an easy environment to deploy Python code onto the Pi… if you’ll believe that!) is fundamentally incompatible with Windows 7, and no amount of driver wrangling will change that.
As for Windows 10, what you’re seeing on that serial device is the read-only debug output of the currently running Python script. There’s no repl or shell or anything you can interact with on the other end of that serial connection. It’s just a dump of the error/text output from the running Python script, right onto the serial device.
The file “/home/pirate/output.txt” does exist, however. It lives on the volatile ramdisk storage (reset upon reboot), but you need to SSH into the Pi (either over WiFi or USB) to get at it.
You may be able to SSH in using something like PuTTY and the host “firstname.lastname@example.org” or "email@example.com" - the password for the pirate user is p1r4t3.
You can also use the “other” serial device, which connects to a regular serial terminal. You may have to hit enter a couple of times after connecting to get the welcome screen up, and then log in with “pirate” and “p1r4t3”.
If you update the “wpa_supplicant.conf” file on the SD card of your test Pi with local WiFi details you’ll be able to get connected via WiFi.
Update: and, once connected, see the IoT logging interface at http://piratepython.local:5000 (or substituting piratepython.local with the Pi’s IP address)