Sorry about that, I sent you the wrong link. The correct one is
here.
Without the logs I can't really say what could've caused this, and with a damaged components hive the tools I use to get the logs won't work, so it's a bit of a vicious cycle really.
This sort of corruption is unlikely to happen, you were just a bit unlucky so don't let it put you off doing anything.
As for updating to Windows 8.1, I'm afraid anything you try will definitely fail. The COMPONENTS hive, as the name suggests, contains information on all of the components installed on your computer. Without it, Windows will have no idea what to update and what to remove, so you'll never be able to update your computer again until this is fixed. Installing other MS components (like .NET and Silverlight) might fail as well, but I'm not 100% sure on that.
I know it's a hassle having to reinstall Windows, especially with lots of programs to transfer over, but it's really important you get this fixed so your computer has the latest security patches installed. With malware like CryptoLocker (encrypts all your files and demands a ransom of $300 to decrypt them) out there, it's just not worth the risk.
One thing you could try before biting the bullet and reinstalling is to do a refresh:
How to refresh, reset or restore your PC - Windows Help
The section:
Refreshing your PC without affecting your files
I'm not sure if this will work or not but it's definitely worth a try.
Tom