I have been trying to update Windows 8 to 8.1 with no success. From the Windows store I downloaded Windows 8.1 (a free installation), and near the end of the install (90%) I get the following message:
installation failed--error code 0x80004005.
From the Microsoft forums I concluded I needed updates KB2919355 and KB2919442 in order to install Windows 8.1, but I do not have either of these two updates and don't know where to find them.
KB2919355
and the first result I got was this Microsoft document, which includes a download link.