Windows Update runs occasionally on my machine, but it steals focus when it pops up to remind me to reboot.
Trouble is, this can mean that while writing something, you could force an immediate reboot.
Is there a way to prevent this thing from stealing focus? It seems to me that no modal dialog box should ever steal focus without a delay on accepting input. Especially if that input can restart the machine when you hit 'n'.

This is similar to this question: Preventing applications from stealing focus But I don't think it's a duplicate. We're not talking about "dubious software developers", or third party apps.