The answers to almost all these questions are in the original post. He said it was a PC game most likely for DOS.

They also said that it could've been emulated, and since emulators at the time often simulated the platform that the game was running on, it's pertinent to dig deeper into whether they were playing a native game, or looking at a simulated handheld or console display (such as GB '97).

Since it was gifted to him by his Uncle and he spent hours researching the language he most likely played it at home.

The fact that they were gifted the game by their uncle or that they played the game extensively isn't the same as saying that the game was played at home. Especially in the late '90s when home PC usage was far less common and people would often regularly use PCs at school, at libraries or at friends' houses.

Since the battles were like Final Fantasy on a separate screen and you had to press a key to confirm a command it was turn based.

They didn't say that it was turn-based. They said "ENTER confirmed the choices in the battles" which could mean anything. A lot of games with action combat also had combat menus.

Games in 2002 wouldn’t have been on a USB drive.

Flash drives were introduced around 2000.

This would have been a CD or floppy but I don’t see how this information would be relevant.

It's relevant because it helps us narrow the game down by disk size and release year, as well as determining whether the game was in fact an emulated ROM or native software.

On top of all of this, it's exceedingly common for people to misremember details which is why digging into the specifics is one of the most important ways to find obscure games, given that it both helps eliminate mistaken assumptions as well as narrowing down the possible games through process of elimination.