Windows 8 and later have a function named “Device Encryption”. It allows Windows to automatically enable BitLocker for local disks and unlock them at startup.

However, if you are using a DIY rig or have changed/added some hardware to your OEM machine, this feature might be broken. Therefore, we need to add those devices to the whitelist to re-enable the feature.

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Whitelist the devices

Check for driver updates in Windows Update before doing this, because even though devices without a proper driver won’t show up in the device list, the system could detect their device ID that might not be listed in the whitelist.

1. Open _Reged_it
2. Navigate to Computer\HKEY_LOCAL_MACHINE\SYSTEM\
   CurrentControlSet\Control\DmaSecurity\AllowedBuses
3. Grant yourself access to modify the registry key
   1. Right-click AllowedBuses and go to Permissions
   2. Make yourself the owner
      1. Press Advanced
      2. Next to Owner, make note of what it says (mine said SYSTEM)
      3. Next to Owner, press Change
      4. Enter your username (eg your Microsoft account email address)
      5. Press OK
   3. Grant yourself access
      1. Press Add
      2. Enter your username (eg your Microsoft account email address)
      3. Press OK
      4. Select your user
      5. Tick Full Control
      6. Press OK
4. Under AllowedBuses, create a new String Value
5. Run the following PS script which generates a .reg file (with all found PCI devices) in tmp directory and then imports it silently

$tmpfile = "$($env:TEMP)\AllowBuses.reg"
'Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DmaSecurity\AllowedBuses]'`
| Out-File $tmpfile
(Get-PnPDevice -InstanceId PCI* `
| Format-Table -Property FriendlyName,InstanceId -HideTableHeaders -AutoSize `
| Out-String -Width 300).trim() `
-split "`r`n" `
-replace '&SUBSYS.*', '' `
-replace '\s+PCI\\', '"="PCI\\' `
| Foreach-Object{ "{0}{1}{2}" -f '"',$_,'"' } `
| Out-File $tmpfile -Append
regedit /s $tmpfile

Restart your computer and enjoy the device encryption feature!