Standard midi File

Hi All
Once importing a standard midi file, cubase reads the track names according to MSB, LSB and Program change number.
were is this file located and what is its name? is it editable?
Many Thanks

Once you import a SMF the imported data are part of your current Cubase project. You decide where to save that file. It is not editable.

so how cubase knows that program change 1 = Piano for example, it must read it from a file

Sorry, I was absent for a while.
I think you got the process twisted in your mind.
When you start Cubase you have to either create or load a project. Even if you directly start by importing a MIDI file you will then have to create a project. At that point you will be asked where to save this project. This project will then contain all the imported midi file information but in a Cubase specific format.
Cubase projects are not editable outside of Cubase.

This is not my question.
Once I right click the midi file and I chose open with cubase, it asks me for the destination folder and it creates a new project.
In the imported file, there is MSB, LSB and program change number.
from where cubase reads this GM to know that for example track 1 uses Piano sound? (127,0,1 ie MSB, LSB and program change). is it XML or TXT file?
If I want cubase to write this track as Guitar Not Piano

When you import the MIDI File it imports all the MIDI Data including the Program Change. But internal to Cubase that Program Change doesn’t correspond to any specific GM instrument. Instead it selects a Preset in the VSTi you are using to play the data with. If that VSTi happens to support General MIDI then its instruments will match the GM standard - which is probably what the MIDI File was using.

Most folks remove the Program Change so they can directly control the Preset selection. The easiest way to do this is using the List Editor to delete it. Typically a Program Change message will be at the start of the List. But the editor will let you filter out stuff you don’t want to see - so filtering out Note data can make it easier to find if what you are looking for is buried in the list.

So none of the above happens within Cubase - the Program Change simply selects a Preset on the VSTi playing the MIDI Data. Nothing regarding MIDI Data is stored in XML or TXT files. ALL the data associated with a Cubase Project - Audio, MIDI, Automation, everything is in the Project’s CPR file.

Cubase reads program changes from the midi file that you import.
If the midi file followed the GM standard then a GM sound module like Halion Player SE can be used to play back the tracks with the correct instruments. Feel free to change the programs yourself if they don’t fit. The List Editor is the best tool for that.