After a lot of help from Paul in one of the newsgroups on the list, I fixed my win10 computer.
I had been getting Inaccessible boot device
and also as a result, 0x000000c, or something like that. If you google Inaccessible boot device. youll see the exact error mentioned.
It took 30 elapsed hours and 6 to 8 hours of work.
I almost wish it had dragged on longer so I could have learned more, by fully understanding Paul's posts, and reading on the web.
I don't even know what fixed it, but I think there were only two possible things I did.
I ran: bcdedit /store C:\boot\BCD /set {bootmgr} displaybootmenu True
Paul susggested this. Paul, after I ran this line, it just said "Operation concluded succefully" but it didn't say what it did!! Any chance this fixed it, or was it just supposed to display the boot menu?
Lazesoft was just as confusing. I used one particular thing** in: Lazesoft Windows Recovery which is contained in Hiren's Boot CD.
I installed it on a flashdrive which is much better that a CD, because you can copy or dl software to it, and run the software from flashdrive, like Forte Agent. You can make a file for notes, save it on the flash drive and then use the flashdrive on your laptop or the broken PC after you fix it.
Hiren's includes Firefox, but afaik it doesn't save bookmarks or prior sessions. It forgets everything it knows when you close Hirens. Because it was first written for a CD and I don't think they made changes when people started putting it on flashdrives.
So in a notes file, I kept a list of urls that might help me fix the problem, to read on the laptop after I closed Hirens.
Back to Lazesoft Windows Recovery, the home edition is free. It's organized pretty well. There are lots of things included that I didn't try because I only did things related to "can't boot". I tried Repair MBR, then rebooted with no success. Then I tried Fix Boot Sector, then rebooted with no success. Then I tried Rebuild boot Menu and rebooted with no success. The next step, something like Replace Windows system files, it said was not available in the Home edition (at least for win10), and I was considering buying a better edition, but I was also following Paul's suggestions and leads. Then I tried Chkdsk and it ran too quickly for me to take it seriously, under 45 seconds, but it didn't find any problems.
Many/most of the operations have Undo ability. Plus it seems you can't run twice the ones with Undo-ability, because the 2nd time the button won't even depress, even if it's not the same Hirens session (because of the presence of the .bak files I'm sure.)
** Finally after hours of reading and trying other things, mostly related to Paul's posts, I tried One Step Repair. It said that was for novice users and of course I'm no dang novice, plus I figured it wouldn't tell me where the prolem was and I wanted to know. So I'd saved it for last.But I tried it and this is what it said. I copied it to my Notes.txt:
System Volume: System Reserved,(*:).1.00 GB NTFS
Check and Fix the MBR Check and Fix the boot indicator
Check and Fix the boot sector parameters Check and Fix the boot sector boot codes
Check and Fix the BCD file Check and Fix the file system for the boot partition
Check and Fix the missing critical Windows system files Check and Fix the registry files -- end quote --
Note that afaik I hadn't done the 2nd, 5th, 6th, 7th or 8th tests, because it didn't list them separately. The 7th line about windows systems files, it specifically said was not in the home edition. Was that incorrect or is the 7th line there by mistake? Who knows. (I looked at the list of files in the System Reserved partition, but I didn't look for a complete list to compare it with.)
And it doesn't say what it fixed, if anything.
Hirens is great. I can't speak too highly about Hirens. Even if it's not the most recent version of Lazesoft (no version number is given), it's much better than just putting Lazesoft Windows Recovery on a flashdrive because Hirens has loads of other freeware and shareware, for just any purpose, like administrative-level CMD, partition managers, ImgBurn, Firefox, notepad, wordpad, MyComputer (file manager). See this list:
I hadn't even noticed thise tools that might have helped: BCD-MBR Tools BootIce v1.3.3 EasyBCD v2.3
I think Knoppix is supposed to be similar but I didn't understand it. I know Hirens works. They're up to version 15.2 now, but old versions are good too if they have Lazesoft.