When you enable BitLocker, there is a period of time where BitLocker is slowly encrypting the contents of the drive in the background. During this time, is it guaranteed that new data written to the disk will be encrypted as it is written? Or is it possible that it will be written to the unencrypted part of the drive, and won't be encrypted until later?

1 Answer 1


The drive will be treated as a whole, since it's a Disk/Volume encryption (unlike file or system encryption), everything that goes into the disc will be encrypted as it goes in.


Behavior confirmed in Microsoft Tech Net

Credits to Chris Vasselli

  • Does Microsoft have any documentation that confirms this behavior? I haven't been able to find any. Commented Feb 3, 2017 at 15:50
  • I'm sorry @ChrisVasselli , I don't have any documentation that supports it, it's just the way I know that Full Disk Encryption (FDE) software like BitLocker works.
    – Azteca
    Commented Feb 3, 2017 at 16:44
  • Thanks for taking the time to respond. This is what I thought as well, but I ask because I found documentation for Symantec's encryption product which claims it's not the case for that product. Can you explain how Symantec's technology is different from BitLocker? Commented Feb 3, 2017 at 19:03
  • @ChrisVasselli Yeah If it's not written in the disk yet, It's not encrypted,. Imagine you copy a file from a USB into your computer. The file you just pasted in a folder inside the windows will be encrypted as it is written, the file on the clipboard you used when you did Ctrl + C can be accessed with a memory dump and will not be encrypted, since it was only stored in memory and not in the disk/volume.
    – Azteca
    Commented Feb 3, 2017 at 21:06
  • 2
    I got confirmation of the behavior from Microsoft. Thanks @Azteca! Commented Feb 6, 2017 at 17:59

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .