Bat File Repair & Explanation

need to fix a bat file and explain to me how you fixed it here is the code i dont discuss the prize of payment i only accept what you bid if you want to talk to me about budget i will leave the chat please respect my wishes

@echo off
SETLOCAL ENABLEDELAYEDEXPANSION

REM Define source file, destination folder, and executable
SET "SOURCE_FILE=C:\Users\marti\Music\ver\version.dll"
SET "DESTINATION_FOLDER=C:\Program Files (x86)\PCGameBoost\Smart Game Booster\5.3.1"
SET "EXECUTABLE_FILE=C:\Program Files (x86)\PCGameBoost\Smart Game Booster\5.3.1\SgbMain.exe"

REM Check if the source file exists
IF NOT EXIST "%SOURCE_FILE%" (
echo ERROR: Source file not found: %SOURCE_FILE%
exit /b 1
)

REM Create destination folder if it does not exist
IF NOT EXIST "%DESTINATION_FOLDER%" (
echo INFO: Creating destination folder: %DESTINATION_FOLDER%
mkdir "%DESTINATION_FOLDER%"
)

REM Copy the file to the destination folder
COPY /Y "%SOURCE_FILE%" "%DESTINATION_FOLDER%"
IF ERRORLEVEL 1 (
echo ERROR: Failed to copy file to %DESTINATION_FOLDER%
exit /b 1
) ELSE (
echo SUCCESS: File copied successfully to %DESTINATION_FOLDER%
)

REM Check if the executable file exists before trying to run it
IF EXIST "%EXECUTABLE_FILE%" (
echo INFO: Starting executable: %EXECUTABLE_FILE%
START "" "%EXECUTABLE_FILE%"
IF ERRORLEVEL 1 (
echo ERROR: Failed to start executable: %EXECUTABLE_FILE%
exit /b 1
)
) ELSE (
echo ERROR: Executable not found: %EXECUTABLE_FILE%
exit /b 1
)

ENDLOCAL
exit /b 0