Error 80240FFF when Installing Windows updates is a very generic error. In Common Windows update error explanation page, it is described as ERR_UNEXPECTED_FAILURE.
You may see this error while installing any kind of Windows update, like a feature update or a cumulative update.
Resolution of 80240FFF
Fixing this error might require a series of troubleshooting steps.
- I suggest starting with this guide which is an article from Microsoft support for fixing Windows update errors.
- If the same doesn’t help, you should Reset Windows update in Windows 10 and earlier versions of Windows.
- At last if the reset also doesn’t help, reinstalling Windows keeping everything would be ideal step. See the following: How to do a repair Install using a windows 10 ISO to fix a broken windows
These steps would probably help you to fix error 80240FFF in Windows 10 updates.