ive tried downloading on another pc and got the same problem. can it be my laptops or is the file corrupt or something? im not very computer savvy to be honest

hi ive tried downloading 1.7 multiple times and i cant get it to work on my pc. im using windows 7. i keep getting a screen to repair or delete so i click repair then it says repaired. i then go to open it again and get the same message. this keeps happening. iv deleted evrything and started over so...