Cannot re-enable Bitlocker
I've installed a fresh Windows 10 in a partition on my system, enabling bitlocker. Then I booted Linux from the other partition and overwrote the master boot record with Grub so I could boot Linux and Windows. I also removed an unused NTFS partition, hoping to use it as a shared space between Windows and Linux (don't do it -- Bitlocker needs a NTFS System partition to store the unencrypted boot sector, much like a /boot
directory on Linux).
However, upon restart Windows complained that "something had changed" on my system and asked me for the BitLocker recovery key. As this kept happening I disabled bitlocker with the idea of re-enabling it later, hoping it would reset itself.
Bitlocker's error was:
"An Error Occurred The System cannot find the file specified".
I've tried re-creating the NTFS partition, but it failed to boot. I fixed the boot process by starting from a Windows installer from USB and using bootrec
, the restarting again and using the 'fix the startup' option. However Bitlocker still refused to start. This is related to the error
"The bitlocker Drive Preparation Tool could not find a target system drive. You may need to manually prepare your drive for BitLocker."
There is an interesting description of the process here with a helpful graph
The solution turned out to be very simple:
- Open an elevated command prompt (search,
cmd
, right click and 'Run as administrator') - Go to
C:\Windows\System32\Recovery\
-
Rename the file
ReAgent.xml
:ren ReAgent.xml ReAgent.old
Start Bitlocker
I've spotted the file here but all solutions listed are more complicated.