For several months I have not been able to install the Window updates
(/windows 8.1). When I attempt to do an update (currently 87
outstanding) it does the download, appears to do the installation, then
asks for a restart. After about an hour or it gets to 67% completed
then finally indicates that it could not do the install and will undo
what changes it has made them when I restart I am back to where I
started - no updates installed.

This same process happens each time I try to do an update.

Any idea what could be happening?