I had Windows 10 (which I use primarily) on one drive of my computer and Ubuntu 16.04 on another drive. I updated Ubuntu to 17.10, but it would crash shortly after starting up. Now, what I did next is probably what caused the rest of my problems and I will never do it again, but I'm hoping someone can help me through it.
In Windows, I deleted all of the partitions on my Ubuntu drive and planned to reinstall. The reinstall ended with the same freezing problem, but when I restarted I was greeted with:
error: no such device: (series of letters and numbers which I assume is the device)
error: unknown filesystem
Entering rescue mode...
grub rescue>
I have tried looking around for solutions and it appears I have removed Grub. I have a bootable USB that can boot to the "try Ubuntu without installing" without it crashing, but I can't follow the other answers I've found.
I would like to return to a state where I only have Windows so I can try to get Ubuntu to work at a later time.
Edit: I should clarify that I already attempted to use ls in the rescue mode screen. All of the (hdX,msdosY) returned an error. Also sudo-installing grub did not work either.
Edit2: Looking at this question, I found that all of my drives/partitions returned:
Filesystem is unknown.
Other than (hd1,msdos6) and (hd1,msdos1) which returned:
Filesystem is ext2
I am not sure which of these is Windows and which is Ubuntu. Can I try the solution in the link for either or is there something else I should do first?
Edit3: I tried the code in Update 3 of the linked solution with both of the ext2 filesystems. Both returned:
file '/boot/grub/i386-pc/normal.mod' not found.