I initiated decryption of my bitlocker drive from Windows 8 recovery prompt. Any indication how long it will take?

Solution 1:

The answer is "it is expected." From a command prompt run as admin, use the following to check the status of the decryption:

manage-bde -status C:

Booyah! You should see the following output:

BitLocker Drive Encryption: Configuration Tool version 6.2.9200
Copyright (C) 2012 Microsoft Corporation. All rights reserved.

Volume C: [Windows 8.1 Pro]
[Data Volume]

  Size:                         238.47 GB
  ... Edit: There is more below including decryption status, too much to type ...

Source: Technet on manage-bde command line tool

Solution 2:

Got tired of command line bumping to see. This shows status, progress, estimated time to complete. To exit, ctrl-c or it stops when converted

# Author - Jack D. Pond
# license: Available under the Creative Commons Attribution-ShareAlike License  additional terms may apply.
# Description: DecryptRemainingStatus   
# 
#    1. Escalates to administrator (if not already)
#    2 Uses the "Write-Progress" to create a bar and provide some status
#       information (as well as anticipated length based on current) for
#       decryption status
#
# NOTE:  You need executable status for powershell scripts.  If you get an error:
# If you downloaded this, you need to unblock the script
# See what your current execution ability is:
#   Get-ExecutionPolicy
# Set it to something reasonable (temporarily)
#   Set-ExecutionPolicy -ExecutionPolicy RemoteSigned
# Don't forget to reset it to whatever it was before (In this case, Restricted) after your run the script
#  Set-ExecutionPolicy -ExecutionPolicy Restricted
# 
# @Params
# 
# -seconds [number of seconds in each monitor interval, defaults to 5]
#
# @example:
#
# PS>.\DecryptRemainingStatus.ps1 -Seconds 10
#
# Get "Seconds" param
#
[CmdletBinding()]param(
    [int]$Seconds = 5
)
# Set-PSDebug -Trace 1

#elevate to "Administrator" (Required for manage-bde)
If (-NOT ([Security.Principal.WindowsPrincipal][Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator"))
{  
    $arguments = "& '" + $myinvocation.mycommand.definition + "'" + " -Seconds $Seconds"
    Start-Process powershell -Verb runAs  -ArgumentList $arguments 
    Break
}
[int] $millisecs = ($Seconds -as[int])*1000
[decimal] $xval = 100
[int] $intervals = 0
$xtext = (((manage-bde -status C: | findstr "Encrypted").trim()) -split '\s+')[2]
[decimal] $startval = ($xtext.substring(0,$xtext.Length - 1) -as[decimal])
while ($xval -gt 0) {
    $xtext = (((manage-bde -status C: | findstr "Encrypted").trim()) -split '\s+')[2]
    $xval = ($xtext.substring(0,$xtext.Length - 1) -as[decimal])
    [decimal] $completed = ($startval-$xval)
    [timespan] $elapsed = New-TimeSpan -Seconds ($intervals*$millisecs/1000)
    [decimal] $secsleft = If ($startval -gt $xval) {($intervals/($completed)*$xval)*($millisecs/1000)} Else {-1}
    Write-Progress -Activity "Remaining Encrypted: $xtext Elapsed: $elapsed Completed: %$completed)" -PercentComplete (100-$xval) -status "Decrypting" -SecondsRemaining $secsleft
    Start-Sleep -Milliseconds $millisecs
    $intervals += 1
}
echo "Decryption Finished"
pause