andrew Bell
You've missed the context of the issue... we all know we can manually install the update via image etc.
You're suggesting that we visit each system which is isn't acceptable or viable for 100+ systems.
This is why we have WSUS (and in conjunction SCCM) to push the Update out to our client systems.
Instead of focusing on the symptom (unable to install), focus on the issue (unable to install via).... understand the real world obstructions as they are part of your clients requirement.
Doing these things is the difference between "IT support from your teenage neighbor as they're good with computers" and "IT support from a professional".
To summarise... stop having a narrow focus and instead look at the bigger pricture. Your needs/solution normally isn't the same as the clients.