I'd suggest that whenever you do a download, you should also get the md5sum file thats usually in the same location.
Why? because when you check the md5sum thats downloaded to the one that you get from the ISO file, even a 1 character error indicates that the is a corruption of the download.
Sure, one character isn't much of a corruption, but if it's knackered in an important location, it can (theoretically) mean the difference between getting the distro installed and not.
If you only have windows, then you would need to get a small app to check the md5sum checksum number - md5summer
is what I used to use when I still had windows (it's even easier to check in linux!