If four different Linux distros tell you there's something wrong so that you can't resize your partition, then probably something is wrong. I realize it's a computer you just bought, but it's still possible that something's wrong with the hardware or that there is, in fact, a bad superblock.
Is Windows currently installed? Since it's a new computer, have you thought about reinstalling Windows, doing a ScanDisk, a Defrag, and then trying to resize again?
But just so you know, here's a great guide for resizing partitions with Ubuntu: