[solarbear]

You set the default boot priority in BIOS, and then you can over ride the default with a post launch of boot options, I have a gigabyte mainboard that lets user over ride the default with a boot options menu launcher upon post, , and then i have 4 hard drives attached to it, all by way of sata cables&ports and sata power plugs from the power supply to the hard drive itself. If yours is a uefi mainboard, from what i recall, you disable safe boot and enable legacy boot, then boot options will let you scroll down to legacy boot drives. Then there are the BIOS hard drive configurations, like IDE and Sata and AHCI, Newer UEFI boards use AHCI. If that setting is mismatched, then BSOD hell ensues.

Last i checked, HPs and Dells offer the boot options menu upon initial power up by way of the F numeric keys.

I remember Windows 7 had an issue with wua update process taxing the cpu hard, there is a procedure to stop it and keep the update function working, but it is such a rat race, MS keeps their rats growing faster by the day and it is somewhat of a futile effort for the average home PC user to win the update race ...although it is amusing to read about them trying..

The way i stopped it is by disabling updates in the control panel, then checking for updates manually when it was convenient. that was so long ago, but i remember doing it like that.