Was late getting up this morning as my computer decided to reboot itself and the alarm isn't active until youve logged in. I know I previously had update set to inform and manually download. How do I reinstitute this type of setting or prevent these unrequested reboots.
If it's a version of Windows older than Win10:
Control Panel > Windows Update > Change Windows Update Settings
If it's Windows 10:
AFAIK you can't do it. There's a number of things you could do instead, but not that.
I think the gentlest option would be to alter the 'active hours' setting to suit your needs so therefore Windows won't auto reboot during hours that would be inconvenient for you, though I find it irritating that (at least the last time I looked at that feature) MS insists on having an upper limit for the number of active hours per day that's nowhere near 24.
In your case to use the computer as your alarm clock where presumably the alarm goes off at a reasonably normal morning hour you might have to look at the 'active hours' feature the other way around being to set it to night-time hours so in theory it won't reboot during the night.
Another option based around active hours is not to have a login password so Windows just logs straight in and therefore your alarm is active.
Another option under Settings > Windows Update is the pause updates option. The first option you see allows you to pause updates for 7 days, another under advanced settings allows pausing for 35 days apparently. You could then unpause, hand-hold it through updating, reboot, then pause updates again?