w810i...I'm confused,need help

[Khaba]

...I was reading the guide. Your precision about files is really appreciated, but please reply also at my other question: you think that can i solve the problem in the walkman player ?

(i understand that the custom pack is not a file to download but only a code to be inserted in xs++ , is it correct? )

Yes, I think your Walkman problem will be solved.
Custom pack is not a code, thats why it is called "pack" it's am archive that needs to be downloaded, it contains more files, and needs to be uploaded to the phone with XS++ or SeTool.