In our college wifi, maximum file size downloadable is 20mb. is there a way to download large files in 20mb blocks and combine later? any help on this is deeply appreciated.
You could try a download manager like FlashGet. They can often split downloads into chunks and recombine them later as you suggest. Whether or not this would be helpful in getting around your school's network policies depends on how they're set up, but it's worth a try.