I need your help. I downloaded 4GB ZIP archive file last week. I extracted it in my computer and saved the ZIP archive in my Pendrive. Next day my brother formatted our home system. We had backup files for our data which were stored in external hard drive. I restored the backup files successfully, but couldn't restore that ZIP archive file. Then I realized that I didn't backup my ZIP archive. But I was at ease as I saved the ZIP archive in my Pendrive. I copied the file into my system and then tried to extract it. But I just couldn't. Then I tried to extract it from the Pendrive, still I was unable. Whenever I tried to extract it I received this: "Cannot open file, it does not appear to be a valid archive". I know it's damaged. What shall I do now. How to extract it? Please help.