I periodically get problems with Service Host Local System (13) hogging CPU.

It starts, takes 25 - 30% of CPU and never stops. I think the problem is Windows Update, as I can 'cure' the problem when it occurs by either stopping or restarting the Windows Update service.

My current Windows Update settings are to never check, as I prefer to take care of it myself (and had other problems with resources when I let it do its own thing).

So my question is, given I have it set to never check, why is the Windows Update Service starting itself so often? (Sometimes 3 or 4 times per hour)

And how can I stop it behaving this way?