Score:0

Ubuntu crashed now Windows 10 doesn't boot

id flag

Ubuntu crashed causing my computer to reboot. Computer no longer starts Windows 10 but instead boots into GRUB.

Before I begin I must state that I am not a computer nerd. I use computers solely to use apps such as word processors to write. So I don't have a clue what you are talking about if you tell me technical computer stuff without details. That is, don't assume I know basic stuff, I would rather you tell me something I know then leave out important details and I do something that makes things worse. If you can't tell I'm worried I'll do something like erase my harddrive by accident.

Here are the details. My laptop came with Windows 10 installed. However, people I know kept telling me that Ubuntu is way better then Windows and that I should switch to it. Afraid of Ubuntu trashing my computer and I not being very computer knowledgeable I was unwilling to install Ubuntu on my laptop. But six months ago I came across a web site that explained how to install Ubuntu on a USB drive so it would be completely separated from Windows. I thought this would keep Ubuntu isolated from Windows but apparently I was wrong.

A couple of days ago, while using the Ubuntu desktop I was editing a simple text document using the text editor that comes with Ubuntu. when Ubuntu crashed. My computer rebooted but instead of rebooting into Windows 10 it came up with GRUB. Holding down the power button I tried to reboot several more times but each time it came back with GRUB, If I understand correctly GRUB is the boot loader that Ubuntu uses (but I'm really not sure).

Since I now owned a 5 pound paper weight instead of a laptop I grabbed my tablet and did some searching on the internet. I finally found the following commands to give to GRUB which will boot me into Windows 10 once again.

insmod part_gpt

insmod chain

set root=(hd0,1)

chainload /EFI/Microsoft/Boot/bootmgfw.efi

So I was able to get back into Windows 10, however, each time I turn off my computer it reboots back into GRUB and I have to enter all the above commands to start Windows. Also I can't get into the Windows Troubleshooting screen to use it's boot repair program.

When I turn my computer on I want it to once again boot into Windows 10. After more research I came across this GRUB command:

bcdedit /set {bootmgr} path /EFT/Microsoft/Boot/bootmgfw.efi

My impression is that this command will set Windows bootloader as the default once again. However, I am not sure about that and don't want to do any more damage to make things worse by entering command I don't understand. So I thought I'd ask for help. I would really appreciate any help anyone is will to give.

Thanks S. Thomas Bradley

ChanganAuto avatar
us flag
IF UEFI then you can - and should, temporarily - change the boot order at UEFI ("BIOS") settings > Boot menu to "Windows bootloader manager" so to avoid issuing those commands every time. You can then troubleshoot Ubuntu which is the only on-topic part.
Nmath avatar
ng flag
Setting boot priority is a function of your motherboard and is unrelated to any operating system. You need to edit your boot priority in BIOS, not by running any commands in any operating system. Running commands you found on the internet that you don't understand can cause some serious problems and you should never do that! Instead, since this is a hardware/firmware issue, read the documentation for your motherboard if you cannot figure out the BIOS settings or how to access them during boot. Every motherboard is different.
Score:1
gp flag

A bootloader is a little piece of software that starts up when you boot your computer, and it it turn starts up the main OS. Think of it a bit like rocket stages, or jump starting a car. GRUB is indeed the bootloader ubuntu uses. It can directly boot linux, and it also usually has an entry that you can scroll down and hit enter (under "ubuntu" and "advanced options for ubuntu") to tell GRUB to "boot" windows by handing off control to the windows bootloader. Your chainload command seems to just be doing the manual equivalent of doing that. (If any of this is wrong, someone correct me please)

I know I've accidentally deleted my windows bootloader before messing with partitions, but that doesn't seem like your problem here. If it was, trying to boot into windows would just give a "no media found" error.

It sounds like you can boot into windows, just inconveniently?

Do you want to boot into windows when you boot, automatically? This would mean you have to go into your motherboards boot menu and manually select Ubuntu each time you want to use it. If this is what you want, try going into your BIOS/UEFI (your motherboard's settings menu, usually delete or f11 or something as you are booting. Or the bottom option in GRUB, the "UEFI system settings" or whatever, is an easier way.), finding a tab that says boot and something that looks like "boot order" or "boot priority", and setting your windows install at the top, before your ubuntu install.

If, instead, you want to boot to GRUB, and then select either windows or Ubuntu within the menu, and windows just isn't in the menu, try this. Within ubuntu, run sudo os-prober in the terminal (command line). If it detects your windows install, run sudo update-grub to add the GRUB entry.

Hope one of these things helps, they should for the most common problems like this. I will say that you are pretty unlikely to actually damage your windows data, even if you make it unbootable, by messing up the bootloader. The bootloader is in a separate area and messing it up can leave the main os untouched. Still be careful, but don't worry too much.

id flag
Thank you. I'll be rereading this again over the weekend. I only want to boot into Windows 10 when I startup my computer and not into Ubuntu. I will try out what I can and get back to you. And thank you for the assurance that I can't do any more harm.
gp flag
Yeah. To be clear, you can do harm, it's just not likely if you aren't deleting partitions or something. Specifically, windows not booting does not equal windows data destroyed. Probably back up stuff though, just in case. You can do so from either OS, put it on a separate device
id flag
Thank you very much. I went into the BIOS as suggested by zoup123 and was able to repair this problem.
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