One is a Nextbook tablet if you look it up this is a tablet with a micro SD slot and a keyboard attachment that has USB ports.
The other is a D255E-2677 Acer. Same issue. This is a netbook but still works and holds a charge.
Now I am not knowledgeable about these things, but I paid for them and I got a feeling someone out there knows how to make these work in some way.
Both have corrupted boot restore partition. So that is out of the question. I have done what I can and with the tablet I don't even know how to change the boot order. With the net book I can. Pretty sure I could get it to boot from the SD slot.
This is info on the Nextbook tablet
If you can help great
Does the Nextbook tablet have some sort of safemode you can boot into? This is a different model but it's made by the same company and might do something with yours.
As for the Acer netbook, You might try a USB optical drive and see if you can boot a recovery disc/live disc and go from there.