From Microsoft won't fix Windows 0x80070643 errors, manual fix required:
Additional information is available in the referenced article including links to the Microsoft articles with steps that will allow the installation of the update to succeed.
I just hope he doesn't get interested in the lovely china on the table next to him. I had to put a lot of things away when I got a young cat who jumped and investigated everything. Every time I think about bringing it out again, I decide to wait another year. He's a great looking cat though!