Thanks for the reply. Sorry I was typing in a panic and angry state, since I was the one that triggered all of this last night. =)
Let me take a step back and give you the information you need:
Currently, I cannot boot into either my Windows 10 install or my Antergos install on my Dell XPS 13 (9350) laptop. When turning on my computer, I see the following in my grub-menu:
Screenshot 1 - https://imgur.com/a/xnc1q
You can see there are multiple Windows 10 entrees now (compared to yesterday). I tried repairing my grub menu (more details below) and those extra entrees popped up. Below, is a screenshot of the errors I see when selecting each OS:
Windows 10 (#1 and #2 Entrees) Boot Screenshots - https://imgur.com/a/mEVZ9
“Real” Windows 10 Entree Boot Screenshots:
Antergos Boot Screenshot - https://imgur.com/a/DilSf
How This Happened:
So, I was trying to install the Windows 10 Fall Creators Update (officially released yesterday). Every-time I tried installing the update, I would get a “We couldn’t update the system reserved partition” error message. Doing some googling I found this was due to my 'System Reserved" partition not having enough space. I looked, and it was only 100mbs, and sure enough mine was using 90mbs on the system reserved partition.
So, I read some people tried to grow (extend) this partition, and that’s where all the fun started. I used a partition tool, and grew the System Reserved Partition to 200mbs total. As far as I can tell that worked successfully:
All Partitions Currently - https://imgur.com/a/OwI8T
You can see that ‘volume 2’ is now successfully 200mbs (The System Reserved Partition). After I restarted, then all these problems started with things not working correctly.
What I Tried To Do To Fix The Issue:
I tried a few things to see if I could fix the issue last night. From the Windows side, I did this based off Dell’s recommendation of the System Partition / Repairing EFI:
Link - http://www.dell.com/support/article/us/en/19/sln300987/how-to-repair-the-efi-bootloader-on-a-gpt-hdd-for-windows-7--8--81-and-10-on-your-dell-pc?lang=en
I then saw on reddit someone mentioned this could actually be a GRUB issue, not an issue with Windows. So, @joekamprad I found a document you penned that discussed repairing GRUB here:
Link - https://antergos.com/wiki/miscellaneous/how-to-fix-grub-with-efi-boot/
I tried to follow this, and that is when the additional Windows 10 entrees showed up. Also, here is output from that command below:
This is not the exact output, as I ran it once and got a successful GRUB repair output…this is what happened when running it this morning again.
So, that’s where I am currently. Basically, resizing my reserved system partition borked my system. I can no longer boot into either Windows 10 or Antergos. I use both OS’s for school, so best case scenario I’d like to recover both if possible, and not nuke the system and format everything to get it working again.
Any help would be greatly appreciated. Please let me know if I can provide any other information in the troubleshooting process.