I don't know why, maybe it's all the work software that only runs on windows but I'm upgrading to 8.1 today. So far, none of my three computers at home can upgrade. One HP, one iMac, one Macbook, all the same error, boot partition needs to be repaired after update. This is the official off the update store page, not iso or download. If I cannot upgrade them, I'm downgrading them all to windows 7 on bootcamp as that's the only way I'll be able to keep the software up to date before windows 7 no longer is updated. Anyone seen a workaround yet? I need to reinstall it again to get more details.