Back to DOS after deleting Windows partition? Boot Error 0xc0000225

Just for future reference to those who stumble on this:

If you've left the OEM partition intact, the problem can be fixed thus:

1. Use a LiveCD with partitioning tools (GParted Live if you prefer GUI)
2. Remove the partitions you created upon installation. If you aren't sure, mount them all and check the contents, it's obvious what belongs to your latest installation (Windows 8 in this case).
3. Remove these partitions. If one of them is bootable, that's fine, just mark the remaining OEM partition (freeDODS in this case) bootable (Note that many OEM partitions contain an OS installer, eg Windows Basic/Home).
4. If step 3 isn't enough, install GRUB from your LiveCD and set the default boot partition as your OEM one (FreeDOS in this case). See here (GRUB is on most LiveCDs): https://www.gnu.org/software/grub/manual/html_node/Installing-GRUB-using-grub_002dinstall.html (It looks daunting, but the first section is all you need to worry about)
5. If your OEM partition is an OS, you're good to go. If it's the actual installer for, just follow the the installer guidelines or, if present, use the "Factory Reset" option. Your MBR will be overwritten by the OEM OS installer and this will leave the computer as good as new.

If you've deleted the OEM partition, then you're in trouble. Your only option is to attempt a partition recovery which will probably fail. Here are some point of salvation:

1. If you had FreeDOS, you're in luck because a stock version is downloadable for free. So wipe the disk, download FreeDOS, install it and it should ship with a bootload that'll overwrite everything before.
2. If you had Ubuntu Linux, Fedora, or one of the few that some OEMs ship, check the default version on the OEM's site, download the installation media and reinstall it.
3. If it was a Windows install, I'm afraid you can't do anything without committing and act of piracy (and as crazy as that sounds, it's true; your MS Windows licence can't be used for a pirate copy of the exact same build) so I can't tell you to how to restore it because then I'd be committing a crime, as would StackExchange for publishing my post. Hopefully, though, there's a hint in this point.

Generally About HP & DOS: FreeeDOS is the DOS that ships by default on HP notebooks that give you the option of OS (under "customise"). Therefore downloading and reinstalling a stock FreeDOS should be fine since it should overwrite the MBR with the bootloader ships with FreeDOS.

In terms of luck, you may get an OEM, like in this case, who will take the product back. However, if you don't want to return it, hopefully this post is of some use.