Hello everyone! I'm new to the forum. I apologize if I'm not up to date with the computer lingo, as I'm not a seasoned computer user, but I have a fair amount of understanding in computers.

I have an issue when trying to boot up my hard drive and don't know how to proceed.

So long story short: my HP laptop suffered (what I suspect is) a circuitboard problem and is out of commission.

I had Windows 7 and Linux installed on it and it had grub so I could select which OS I wanted when I booted the laptop up.

I also have an Acer Aspire PC and I wanted to take the laptop Disk Drive out and plug it into my Acer (I have a USB adapter for it) so I could boot up my windows 7 and Linux desktops on my Acer since my laptop is finished.

Unfortunately when I put my laptop's disk drive into the adapter and plugged it into my Acer and selected it on the boot menu, I was immediately given a blank screen that said, "error: no such partition" and it gave me a grub rescue prompt.
I know my OSs are still there, I just can't access them because there's no grub anymore apparently and I doesn't wanna boot.

Does anybody know how to fix this? I couldn't find anything useful online anywhere.

Side note: I've done this before, and booted a USB disk drive with my Acer and had no issues. But it only had one Linux OS on it, and no grub.

Thank you!