You're on the right track. I see, in my installation, the two scripts that you do(of course, they're actually named "mysql_fix_privilege..."). But I've also got the "mysql_fix_privilege_tables.sql" file, that you seem to be missing.
Either your copy of MySQL was flawed and didn't come with the script, or the script was accidentally deleted/renamed/moved on your PC. I'd suggest reinstalling mysql(probably uninstall current copy first). If that doesn't work then, if it's possible, download a fresh copy of mySQL and reinstall. Maybe choose a different mirror to download from?
Your English is fine...and it's certainly better than my Portuguese!