How To Fix Can't Boot - BCD errors?

[arthur brogard]

I think this is probably well covered somewhere. If someone could point me in that direction.

I have a machine that won't boot into Win10. I got a message that the BCD was invalid.

I have a USB win10 install/recovery thing. I'm not sure what to call it. I made it in response to the advice I got somewhere when I was asking about problems such as this.

I tried to use it to go to a command prompt and follow directions for fixing the BCD.

But when I got to the /fixboot command I got an 'access is denied' message.

So I tried to use it in it's 'normal' manner and I picked the option for saving my files.

It wouldn't allow that. Because I was using a USB, it said.

So now it looks like all I can do is go for a new install of Win10.

After that I might be able to get something from a Macrium backup. I'm not sure.

The diskpart commands did reveal that there's a 'recover' partition on that disk. That doesn't help at all?

 

[Saltgrass]

We have seen literally thousands of these situations. Sadly, I have not seen a definite reason as to why they are happening.

If you take the message as it states, the BCD store, which is a listing which directs your boot sequence is corrupted or missing for some reason. It is important to know whether you have a Legacy (Older) or UEFI system to know what type of boot you use. If you can get into the advanced repair options and go to startup repair it should help but may not be able to complete. If may even take multiple (3) runs to repair some problems.

You can check your Bios for a primary boot device. For a Legacy system it should show a drive and for a UEFI system, it should show a Windows Boot Manager. Make sure one of those is set for your primary boot.

If you can get into the Command Prompt, there are some commands you could run. First, try

bootrec /rebuildbcd

which may help and try rebooting depending on what the results show. If it shows 0 Windows installs found that means the entry may already be in the BCD store. If it shows 1, then add it and try rebooting.

If that doesn't work, you can get back into the Command Prompt and try

bcdboot c:\windows

Which will copy a new template of the BCD store to your system partition. If it completes, recheck your primary boot device in the Bios and try booting again. With this command the OS would need to be on a designated C partition. When booting from a USB drive, it may not be. The Diskpart utility used in the Command prompt will show partition designations. Type:

Diskpart
lis vol

and check for drive letters to confirm if the OS partition is C. When done, type exit to leave Diskpart.

There is always a chance your drive is having a problem so recovering your files would be important. I do not know what your are trying as how to save your files but you would need a drive large enough to handle them.

The option to create a bootable version of a Linux OS, such as Ubuntu would be an option as you can use it in a Live manner and not install but still have access to copy off your files.