How to recover unused disk space from BitLocker drive on Windows 7

[Afznotermi]

I had installed Windows 7 as my operating system on my machine. I had also installed BitLocker Drive Encryption program, in order to protect my machine from any kind of loss data and information. Recently i had copied 20GBytes of data into personal safe. I found that I could not search my files properly,so i deleted the data but the C drive free space has not been released and I have lost 20GBytes of space. So, i would like to know that how to recover unused disk space from BitLocker drive on Windows 7? Is there any way to recover this space? Any help you can provide would be greatly appreciated. Thanks.

[Devasis]

BitLocker Drive Encryption is available on some versions of Windows Vista, Windows Server 2008 R2 and in some editions of Windows 7. You can only shrink filesystem/lvolvs if you have OnLineJFS installed. BitLocker provides enhanced protection against data theft or exposure on computers that are lost or stolen, and more secure data deletion when BitLocker-protected computers are decommissioned. If you want to resize all filesystems without OnlineJFS one option is to make a "make_tape_recovery", boot from the tape, choose "Advanced Mode" and then you can resize the partitions.

[Solomon]

First used a another machine and crated a bitlocker partition with windows 7. Just to check how the partition header sector will look like. BitLocker uses TPM to validate the integrity of a system by performing a check of the boot components and boot configuration data. The potential changes could be anything from installed Trojans or root kits that have made their way onto an affected system to a malicious user attempting to boot to the computer or laptop from an alternate operating system with the intention of gaining unauthorized access to the data on the system. This security measure is done to verify that the system is still in the checked state it is expected to be in. Then I used a tool that can view the actual hex data.

[MrChris-]

Sound like you will have to format the partition to allocate the space and try recovering the data that way. I think you should try out defragmentation. If you have used bitlocker to encrypt a 20 GB partition on a drive then you need to unlock the volume in order to see that bitlockerd volume. There are a few situations where you might need to temporarily disable BitLocker Drive Encryption to perform changes or maintenance to a system. If you no longer want that 20 GB used, just delete that volume or unencrypt it. Doing this will allow you to incorporate the changes to the system as part of an authorized change and that would keep the system from going into a state at start up that might require it to be recovered.