This has happened to me numerous times.
If ANYTHING at all goes wrong any time during the install and and files get corrupted or fail to copy of what ever, then there seems to be no possibility of recovering from it.
You have no choice but to start over again. and wipe the disk.
I had a power supply failure during install of Windows 7 and found later on that updates were not working.
None of the standard fixes work, re-installing by upgrade does not work, nothing works.
In the end I given up any hope of fixing the problem and have wiped the disk and re-installed.
I wish Microsoft would stop wasting time making useless cosmetic changes and concentrate on fixing these irritating problem and making their product efficient.