If i restore windows 10 will it break my manjaro installation?

Hi , i have a duall boot installation with manjaro and win 10, buy i want to give more space to manjaro (it have only 100 gb and that freaks me out). So i was planning to restore windows 10 and defragment to give the maximum space possible for manajaro
My questions are . My dual boot will crash if i restore windows 10? and is there a better way to give more space to manjaro?

Welcome here, @Sadsandman1 :tada:

before thinking about restoring Windoze I would try to defragm the Windoze partition with Win tools and then to shrink it with Win tools. Make sure to make a backup of valueable files upfront.

In addition, every time you do Windows Updates or Restores you run the risk that Windows replaces the grub bootloader with its own. Your Manjaro install will still be there but you can’t boot it anymore. To fix that, you need to boot from a USB Stick containing a Linux distribution. The Manjaro install image should be fine for that. So make sure you have that ready before you put you plan into reality.

Then restore grub as mentioned in those articles:
https://wiki.manjaro.org/index.php/GRUB/Restore_the_GRUB_Bootloader#Reinstall_GRUB

What you wrote apply to a failed/normal Windows update that rewrites the boot thingy. If he restores Windows, he’s most likely talking about a feature in the computer BIOS to restore the disk in its initial state from factory, from what I’ve seen so far I wouldn’t be so confident about Manjaro being untouched. From what he described he created a partition on the computer drive so it may be possible that the restoration recreates initial partitions and files.

Also I doubt the GRUB restoration instructions you posted apply to him as I have yet to see a Windows 10 computer in MBR (it is possible, but I doubt that it is the case). The Manjaro wiki is the way to go, following what suits the system of course (UEFI most likely).

But before thinking about that, Wollie posted the procedure he should follow to give more space to Manjaro (I think it misses the part to expand Manjaro partition to take the newly unallocated free space back).