Hi I encrypted C and D drive using Bitlocker. Then i change UAC setting from low to default level. After restart my notebook my D drive keep lock and need to key in PIN everytime restart my notebook. When i use auto unlock D drive it say "data error cyclic redundancy check" . Have anyone encounter this error on Windows 7 by using Bitlocker. Thank you.. regards sam

Hi Sam, Please check the following: 1. Was the D driver successfully decrypted after receiving the error message? 2. If you change the UAC setting back to low, will the issue occur? At this time please also try to run the command Chkdsk to check the disk: Chkdsk Hope this helps. Thanks.Nicholas Li - MSFT

Hi NicholasMy default UAC levelis low. My both partition C and D are encrypted with bitlockerI go to increase 2 level UAC and the system ask me to restart.When i restart my D keep lock. So i will need to key in PIN everytime login windows 7.I try Chkdsk already but no luck. Unless i decrypt my D drive and encrypt back D drive. After that i will never face the error even i set the UAC low or high.Thanks,,...

same error ("data error cyclic redundancy check") just happened to me for the first time today, and LOL: on drive D:\ as well. This happened after a Windows restore with a system image (after a crash, off topic here), which meant I had to re-encrypt drive C:\ . I knew in advance that the only way out was to decrypt and re-encrypt (D:). There were other bitlockered drives that didn't have this issue with the automatic unlock at boot time, except one that refused to open completely and became accessible again after a reboot. Anyway I'd love to know what message means, ie what sort of error this is... just found this: http://www.sevenforums.com/software/40702-auto-unlock-encrypted-drive-fails-after-image-restore.html system image backup seems to be indeed the culprit

happened to me again after an re-imaging of mys system drive. Had to re-encrypt C: (which was expected and normal), but I couldn't set the other drives to unlock automatically at boot time, getting the cyclic redundancy check error again. But this time I got the solution: from a command prompt as admin, type: "manage-bde -autounlock -clearallkeys C:" ...which will clear bitlocker master unlock key... then reboot, unlock the data drives again, and find that you can now set them to unlock automatically at boot time again. So ,thanks to the author of this article here: http://www.mcbsys.com/techblog/2010/08/re-enable-bitlocker-auto-unlock-after-system-volume-restore/

happened to me again after an re-imaging of mys system drive. Had to re-encrypt C: (which was expected and normal), but I couldn't set the other drives to unlock automatically at boot time, getting the cyclic redundancy check error again. But this time I got the solution: from a command prompt as admin, type "manage-bde -autounlock -clearallkeys C:" which will clear bitlocker master unlock key... then reboot, unlock the data drives again, and find that you can now set them to unlock automatically at boot time again. So ,thanks to the author of this article here: http://www.mcbsys.com/techblog/2010/08/re-enable-bitlocker-auto-unlock-after-system-volume-restore/

Thanks for the reference. Here's the link: Re-enable BitLocker Auto-Unlock after System Volume Restore http://www.mcbsys.com/techblog/2010/08/re-enable-bitlocker-auto-unlock-after-system-volume-restore/ Mark Berry MCB Systems

... just to mention that I find it hard to accept that this thread was posted in November 2009... and no MS rep to post the solution... which was actually an easy one, to find in bitlocker command line tools, if people here, including me didn't think in the first place that bitlocker interface somehow broke after re-imaging the system drive. So a big thanks to Microsoft (insert sarcastic emoticon here) :) ... even though a Google search appeared to be more efficient this time ;)