We tell why in the forum sticky. And the reason it's in the sticky is that your post doesn't need the repeating answer.
Whenever I try to download from my MiniDV Camcorder (Sony DCR-HC36) through USB cable and using Software provided by Sony it downloads the MiniDV into PC but size of Downloaded video becomes huge (1 MiniDV of 1 hour makes a 25GB-30GB of video file. In addition to the above, it makes a file of 1 to 10 minutes video file and I have to send the command to download again and again. Please give solution to this problem.