Took quite some interest in this problem since I use Veracrypt too myself but I don't use FDE. I only use FLE (File level encryption), albeit I have never found myself locked out from my system yet.
so now i'm locked out of my computer and my C drive is also encrypted with VeraCrypt, and my D drive was half way through the encryption process.
Full disk encryption (FDE) applied at this stage, its impossible to recover data unless...
you can
try Veracrypt rescue disk
When you used Veracrypt to do FDE on your C and D drive, you are forced to do this process (according to the article):
The VeraCrypt wizard will force you to create a VeraCrypt Rescue Disk image before continuing.
If your bootloader or other data ever gets damaged, you must boot from the rescue disk if you want to decrypt and access your files. The disk will also contain a backup image of the contents of the beginning of the drive, which will allow you to restore it if necessary.
Note that you’ll still need to provide your password when using the rescue disk, so it isn’t a golden key that allows access to all your files. VeraCrypt will simply create a rescue disk ISO image at C:\Users\NAME\Documents\VeraCrypt Rescue Disk.iso by default. You’ll need to
burn the ISO image to a disc yourself.
Be sure to burn a copy of the rescue disk so you can access your files if there’s ever a problem. You can’t just reuse the same VeraCrypt rescue disk on multiple computers. You need a unique rescue disk for each PC! Consult VeraCrypt’s documentation for
more information about VeraCrypt rescue disks.
If you forgot your password, AND/OR forgot to burn the rescue disk before you got locked out of your system, then its totally gone sadly. You need both.
The only thing I'm curious about this solution is that both the how-to-geek article and a user from a link that I will post below both suggest
using a CD/DVD to burn the VeraCrypt rescue disk.iso - whereas we all currently use USB flash drives to boot from rescue disks. I would suggest just burning to both so that in case the USB doesn't work, then CD/DVD booting should work.
do you have a clue what made the problem?
and what can prevent it next time i install?
if that were your setup of having FDE, I would second using macrium reflect to do regular backups in the event that you get "locked out" of your system.
Never trusted built-in Windows tools to do the job for me either.
Also
from this post, it seems that Windows update can screw you up if you use Veracrypt for FDE, causing you to be locked out.
You need to disable Windows 10 updates to prevent the bootloader from being messed up by Windows when it updates.
I encrypted my Win10 system partition with Veracrypt a couple of years ago, and have recently and belatedly allowed the laptop to update Windows. After a couple of reboots it now fails to boot other than into the Windows recovery options.
Windows 10 updates is notorious for screwing up bootloaders, especially with Linux (on Windows Linux dual setups). Since Veracrypt uses a bootloader to load the drive it encrypted, then it is susceptible to the same.