Dual boot machine - I deleted old Linux partitions and broke Grub.

I just want to repair the MBR so Windows can boot, but I don't have a recovery disk.

I've spent /ages/ creating a bootable USB with Boot-Repair-Disk on, but it doesn't start ("can not mount /dev/loop0 (/cdrom/casper/filesystem.squashfs) on //filesystem.squashfs")

So any suggestions on the simplest way to restore it?

And why is it so bloody complicated to tell a computer to boot from partition X on drive Y? :@

Ok, so I re-mirrored the disk to get things booting again, and found instructions for creating recovery disk without needing an ISO, so I'll do that tomorrow and figure out if Grub has a proper uninstall method before I start re-doing partitions.

# dd if=/dev/sda of=/path/to/mbr.bak bs=512 count=1

I can choose boot drive and partition from within the bios on my laptop, guessing you've checked if that's possible on your machine?

That'll be either UEFI or GPT doing that.

I don't got none of those.

That copies an MBR file to the first 512 bytes of the disk, right?

One of the many useless bits of information that lodged itself in my brain from the numerous pages of irrelevant crap I read through yesterday is that it's not safe to assume that's always the case.

MBR restored, old partitions removed, Windows still boots, 100GB free on C, and an evening of robocopy /mir /dcopy:t to look forward to.

//WOOT//

Ah yeah, uefi I think. Useful if you've got it!

Almost all done... after shuffling partitions I've got 40GB unallocated on my second disk which is before the main partition and when I try extending Windows wants to do some "dynamic disk" bollocks to use it. Grrr.

A quick search says GParted can just extend partitions backwards, so that'll be tomorrow's task and then I'll finally be all fully upgradeded.

Nope, it copies the mbr + partition table to a file, which can then be restored from a linux boot disk in the event said mbr is hosed.

"Moving a partition might take a very long time to apply."

Well that's a useful message. How long is "very long"?

Search reveals no information whatsoever.

Fuck it, can't be that bad. I'm enlarging the partition not moving it, so at most it should just need to update the index table file offset values or something, no data needs to change.

"3.96 GiB of 1.78 TiB copied (41:40:50 remaining)"

Oh fucking hell!!! :@

Even *if* it recognises that half the bloody disk is empty, that's still 21 hours just for an extra 5% of space.

"8.00 GiB of 1.78 TiB copied (46:41:52 remaining)"

It's gone up by five hours! :@

The original clone only took three hours - lets see what happens when I click this cancel button...

Hrm, so it looks like it cancelled and restored the original partition info, and the data is all still there - I guess since I did it before it went past the 40GB point. Yay for not having to spend another three hours faffing.

Heh, so this is why I've got a 32GB pendrive with Windows recovery on.

If I'm reading my ramblings correctly, it wasn't any help and there's no reason not to overwrite it ... so why do I feel like the day after I do, Windows will suddenly break on me... :'S

I thought you said the pendrive was useless for windows recovery anyway? Besides, the things are dead cheap.

They are, which is why I went out at lunchtime and just got a new one.

It's frustrating that every supposed-to-be-quick task I try to do turns into an odyssey.

Here's a new-to-me debian based os. Can't tell if it's super-easy, or just dumbed down Gnome

https://endlessos.com/

I vote dumbed down Gnome.

Turns out it's not even proper Debian...
https://support.endlessm.com/hc/en-us/articles/115004795106-Is-Endless-OS-based-on-Debian-
https://support.endlessm.com/hc/en-us/articles/115000097483-Why-can-t-I-use-apt-get-dpkg-dnf-or-rpm-commands-

Does look like a kiddie toy.