so you're in the grub shell, right? "can't find vmlinuz you have to load the linux kernel" or something?

<code>
ls
</code>

should show you stuff like 
<code>
(hd0) (hd0,gpt3) (hd0,gpt2) (hd0,gpt1) 
</code>

you don't have to include the ''gpt'', going forward.

in turn, ''ls'' each partition:
<code>
ls (hd0,1)
ls (hd0,2)
ls (hd0,3)
</code>

one of them should tell you ''Filesystem type ext*'' - that's your linux filesystem. hopefully. Let's look inside it:

<code>
ls (hd0,2)/
</code>

that trailing slash is vital.

ok, did it show you a bunch of directories, including ''/boot?''

also:

<code>
cat (hd0,2)/etc/issue
</code>
should tell you your OS's name. Might be important info if you're dual booting.

<code>
ls (hd0,2)/boot
</code>

you should see ''vmlinuz-(etc)'' (let's say ''vmlinuz-6.2.0-20-generic'') and ''initrd(something).img(maybe something)'' (let's say ''initrd.img-6.2.0-20-generic'').

Good shit: this is our drive.

<code>
set root=(hd0,2)
linux /boot/vmlinuz-6.2.0-20-generic root=/dev/sda2
initrd /boot/initrd.img-6.2.0-20-generic
boot
</code>

**''linux'' //must// have ''root=(device)''**. if you fuck that up, reboot. 

ideally you're in your operating system now. You'll have to update the bootloader. there's a great program (that somehow isn't installed by default??) to handle this automatically: ''update-grub''. install it, sudo run it.