If you are seeing errors specifically related to part03.rar , try these steps:
: Compare the size of part03.rar with the other parts. If it is significantly smaller (and isn't the very last part), it is likely an incomplete download. Call.of.Duty.Modern.Warfare.part03.rar
To avoid the risks of corrupt or unofficial .rar files, it is safer to use official launchers which handle file verification automatically: : Use the Battle.net App or Steam . If you are seeing errors specifically related to part03
: Single segments often corrupt during download. Delete part03.rar and download it again. Call.of.Duty.Modern.Warfare.part03.rar