I'm sorry.
I am going to bow out of this conversation.
I just don't have the time or energy for this right now.
There are hundreds, likely of different FX2 based devices, dev boards, MSOs, LA's etc, - some cost less than $5, that work fine without any extracting of anything or downloading of anything proprietary. They don't need it.
This is demonstrated by the inclusion of the sigrok-firmware-fx2lafw in the main Debian distribution. (not something that ever happens for non-free software)
It wouldn't be there if it contained any proprietary firmware.
I have never needed to do anything like you are describing.
If you have questions, you should email Uwe Hermann <uwe@debian.org>
who is the Debian package maintainer. He is also a user here, offhand I don't know his user name.
You shouldn't buy products that claim to be something they aren't. Ebay's policy is to not carry counterfeited products if they are made aware of it.
If you try to install another manufacturers firmware on a product thats not theirs, you're not unlikely to brick it.
Since you use Windows, which attempts to "update" things, maybe you already did?
Here is the description of the sigrok firmware.
"Firmware for Cypress FX2(LP) based logic analyzers
sigrok-firmware-fx2lafw is an open-source (GPLv2+) firmware,
implemented from scratch, that allows you to use almost
any device or eval board that has a Cypress FX2(LP) chip
as a logic analyzer via libsigrok (and a suitable frontend)."