All it does is to list all attached drives, and go through them one by one according to the boot order. How does the BIOS decide which partition to boot from anyway? Won’t it just look at the MBR partition table and pick the first bootable partition?Īs we found out quickly, the BIOS in fact doesn’t really care about the partition table at all. How could one possibly diagnose something like that without having physical access to the device itself? With lots of on site customer help, we quickly narrowed things down to an attached USB flash drive, and we immediately suspected that the BIOS is trying to boot from that drive.īut how was that possible? None of the partitions in the MBR on that drive was marked bootable, and there wasn’t even a bootable OS on the USB drive. When we encountered it a few months ago when a few of our customer devices refused to reboot, we were a bit puzzled at first.
#FIX WINDOWS 7 BOOT USB ISO HOW TO#
In this short post, I’ll demonstrate how to reproduce the blinking cursor problem, and how to “fix” the MBR to ensure the computer still boots, regardless of the boot order.Īssuming that your system is booting via BIOS (not UEFI), you’ve surely encountered the infamous blinking cursor at least once: Now, while dozens out of over 60k isn’t that much, our customers rely on these devices, so it’s not acceptable to have them not boot properly.
Unfortunately, it didn’t happen to my computer, but to a few dozen of our customer backup appliances during their scheduled upgrade/reboot. If you have no physical access, things are a bit more tricky: This exact thing happened to me at work the other day. If you have physical access to the machine, simply remove the USB drive and/or change the boot order to pick the OS disk first.
#FIX WINDOWS 7 BOOT USB ISO CODE#
Have you ever rebooted your computer only to see a black screen with a blinking cursor? If you have a USB drive attached, chances are the blinking cursor is caused by invalid bootstrap code in the Master Boot Record (MBR) on that drive which has caused the normal boot execution to stop without returning control to the BIOS. Linux, Virtualization USB disk causes blinking cursor at boot how to “fix” the MBR bootstrap code
0 kommentar(er)
