Cant delete 2nd OS during boot

Hi, sorry if this has been asked, I did a search for this first though, and couldnt find a solution. When I boot my windows 10, it gives me the option between my win 10 and Debian (uninstalled) options. If I click the debian option, it gives me an error message and reboots. Ive tried going to MSCONFIG, but only win10 is listed there. How do I delete this other OS? Im not even sure how it got there, I have never tried a dual boot. TIA

there are a number of ways to do what you want i believe, including deleting the debian/grub entry from within the uefi/bios and making sure windows boot manager is first boot option.

 

probably the easiest method though might be to use easybcd to delete the debian boot option.

 

download from here :- https://neosmart.net/blog/2015/easybcd-2-3/

guide :- https://neosmart.net/wiki/easybcd/basics/deleting-entries/

 

No listing of it in uefi or boot settings, I'm thinking it has something to do with the fact that it wasn't finished installing. (The boot option lists it add "Debian-continue with install") So odd. I tried the easybcd too, no luck there.
I could just change the 'show boot options time' to 0 seconds so it didn't pop up whenever I turn on my laptop, but I'd really like to get to the root cause, if there is one…

not having a uefi pc and never used windows 10, at the moment i can't think where else it would be installed except on the uefi boot partition.

see if this guide helps :- http://linuxbsdos.com/2015/09/05/how-to-delete-grub-files-from-a-boot-efi-partition-in-windows-10/

 

is the pc set to boot uefi or legacy mode? if set to legacy, set it to uefi boot.

 

i know nothing about the Dual-boot Repair tool mentioned here :- http://superuser.com/questions/949219/how-to-fix-windows-10-boot-loader-from-windows

but it might be worth looking into if nothing else mentioned in that topic works.

 

 

do you still have the debian partitions on your drive?

No in fact that's the weird thing, I have never had any Debian or any os other than Win 10 on this laptop. When I check in the disk management tool, it lists my C, D(recovery) and E(cdrom) drive,as well as 4 hidden drives with no letters. None of the space is unallocated though. Not sure if that's Normal..

 

4 hidden drives with no letters.

1 of them might be the debian partition. can you show us a screenshot of all the partitions.

 

don't forget to go into uefi and make sure boot is set to boot uefi and not legacy too and see if that makes any difference.

 

Hmm no..I went ahead and just accidently deleted everything lol. :/ I was following this and accidently deleted the EfI file for my main os
Not sure what the deal with that is, it was a different drive,which I had named L:… But I guess this makes it simpler, in a way. Just gonna reinstall W10 from scratch now..
One thing I did notice that stuck out to me was my c drive was GPT, not ntfs. And the hidden file I was messing with and deleted contained a Linux(?) file /gbr2**.mbr or something along those lines. I do have safe boot enabled, so I'm at a real loss here.

(Just for refrence I found a similar photo I've attached of what my discmgmt was showing; C: was GPT & D: NTFS)
This is my "play" laptop, so it's quite likely I could've downloaded some not so friendly programs that might very been the cause? Who knows

i think you can probably fix the windows 10 boot problem if you have a windows 10 install disk instead of doing a full clean install, up to you though. (maybe even just setting uefi/bios to boot in uefi mode only will also fix the problem, if as i suspect the file you deleted was on the debian partition and not the main uefi boot partition, if the file was on the uefi boot partition then you will still need to use the windows 10 disk to fix the boot problem.)

 

it sounds like "/gbr2**.mbr" was the entry you needed to delete from the file and not the file itself.

 

what's happened i think is someone tried to install debian onto the laptop, but instead of installing in uefi mode they installed it in legacy mode (setting in uefi/bios.)

 

uefi mode uses gpt partition file system, legacy uses mbr partition file system. :- http://www.howtogeek.com/193669/whats-the-difference-between-gpt-and-mbr-when-partitioning-a-drive/

 

with mbr the very start of the hard drive contains the info on where to look for the boot files, which were probably stored on the debian partition.

with gpt the info is stored anywhere on the hard drive in a dedicated uefi boot partition.

 

that's why i hoped changing the boot setting to uefi only mode would stop it offering the choice to boot either os and just boot straight into windows because it would not read the mbr and use the boot menu which i believe would be stored on the debian partition, but just look for the uefi boot partition and use the windows boot manager in there which doesn't have the debian option in it as proven by trying to find and delete it with easybcd.

 

i also doubt it was a malicious file that caused your problems and it was more likely someone deliberately tried to setup a linux dual boot system without fully understanding what they were doing.

 

i only run linux on my pc's and have setup many dual boot systems myself but not actually having a uefi pc myself and never having installed a windows dual boot to one (far as i remember.), means i've never tested and experimented on a uefi system all the different ways linux can be installed to discover any problems and what the easy fixes are, so this is just speculation on my part.

 

sorry i couldn't resolve the issue in a more simply and efficient way for you.

 

Thanks so much for your help, you were very thorough! How would you reccomennd I reinstall win10 now? It came preinstalled, so I don't have the disk. Was thinking I will just get the media install tool and iso and boot from a usb.

long shot but you still might be able to install/fix it using the inbuilt tools.

 

see what options show up when you tap the F keys on power up F8 for example, i've no idea which F key will bring up the advanced or install/repair/diagnosis options so you'll have to try one key only each time you power up until you find the correct one and that's if they still work after you deleted that file. good chance they still will though i'd think.

 

otherwise yes you'll need to create your own bootable media using windows 10 iso you've downloaded/created.