Comment 44 for bug 1090829

I'm speculating, but I suspect that this problem may have to do with the Windows "fast startup" feature. This feature essentially turns the "shutdown" option in Windows into something more akin to a suspend-to-disk operation. As such, any filesystems that are mounted at the time of "shutdown" (perhaps including the ESP) will be left in an inconsistent state. If they're then accessed from another OS (such as Linux), the result could be disk corruption, which could then be worsened when Windows is booted again. (Windows might write back the disk state from before Linux wrote files to the ESP, causing those files to disappear or be corrupted.) This can quickly turn into a real mess.

I'd like to emphasize that this is speculative; I haven't run any controlled tests to see how this feature affects the ESP. The symptoms reported seem consistent with what I'd expect, though, with the possible exception of I/O errors. (Those might occur if filesystem data structures were left pointing outside of the partition, but that seems odd.)

If this hypothesis is correct, the solution is to disable the "fast startup" feature -- preferably BEFORE installing Linux. Various Web pages describe how to do this; for instance:

http://www.eightforums.com/tutorials/6320-fast-startup-turn-off-windows-8-a.html

Ideally, the Ubuntu installer should attempt to detect this condition and refuse to install until the feature is disabled in Windows, since failure to disable "fast startup" will almost certainly lead to problems.