Cannot boot windows anymore after replacing ubuntu with manjaro

[MaxP]

Hi,
First time posting, let me know where I can do better.
Also, this is my second manjaro installation and I am not yet very familiar with it besides the obvious awesomeness.

This morning I had a win11 and ubuntu22 running in dual boot and decided to replace ubuntu with manjaro.

Before I changed anything, the ubuntu boot loader was installed at the first ~100 MB of the hard drive, followed by gigabytes of windows, 8GB swap and ~125GB of ubuntu.
That worked just fine.

I booted the boot stick, went to the installation gui and did manual partitioning.

The 100 MB at the beginning of the hard drive turned out to be, well, not enough for the manjaro boot loader so I unallocated that.

I put the boot section behind the windows section, some swap after that and then the main manjaro partition.

So now I have no idea how to boot windows.
Did I do any very obvious mistakes I do not see right now?

[brahma]

can you boot into windows from bios?

[MaxP]

no, only to manjaro

[brahma]

so by messing with the partitioning - resizing/moving partitions, you messed up windows boot loader…
you have to repair it using windows usb/dvd, look on guides on the internet how to do it… but this windows boot repairing will very likely wipe out manjaro grub, so you will not be able to boot into manjaro, and you will have to repair manjaro grub from manjaro usb, using chroot:
manjaro-chroot -a
then reinstall grub running these commands depending on what you are using, bios or efi:

GRUB/Restore the GRUB Bootloader

if you are unsure about reinstalling grub, just ask here

[MaxP]

aye, thank you so much for that.

I hoped there was an easier way, but ok, I will do the repair and reinstall cycle once more…

So, last question before bed:
I could repair windows, wipe manjaro in the process so I have a clean windows installation and try the “install alongside” option in the manjaro install gui, right?

[brahma]

the repairing windows boot loader doesnt wipe manjaro, only manjaros boot loader/grub…
but yes, you can then just reinstall manjaro using the install alongside option…

[MaxP]

ayeaye, thanks again.

[Will]

I’m a fan of the rEFInd bootloader; installing it from Manjaro should, after a shutdown, find any and all bootable o/s, as well as the bootloader. Pamac has refind and refind-extras.

[MaxP]

So, most of it is working again:

As brahma thought, I messed up the windows boot loader.
To repair it I just needed to:

• Make a windows bootable stick with the tool provided by microsoft
• Boot the stick → Repair your computer
• Go to Troubleshoot → Advanced options → Command Prompt
• execute: bootrec /rebuildbcd
• Restart.
• Reboot the USB-Stick!
• Again to repair your computer → Execute the Start Up repair.

And then I could boot both win11 and manjaro from the bios. (Edit: No manajro repair needed)

Sidenote: I got originally win10 and upgraded to win11 some months ago.
For some reason the repair stick was convinced he repairs win10 instead of 11.

Again, thank you so much brahma and Will. I can access all my stuff again!
Your advice was on point!

Next: Bring second monitor to live (intel and nvidia grafics in my system) and repair grub or try rEFInd, maybe later today or tomorrow.

Edit: execute “update-grub” was everything needed to have the windows boot option in grub.