EFS Issue

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Mouse4440 - 28 Apr 2005 00:33 GMT

Recently I used RIS (Remote Installation Service) to reinstall a
clients workstation because it had been upgraded and had different
versions of Office installed and just generally had issues, but what I
didn’t know is that the user had Encrypted files on another drive (USB
External Hard Drive) so after I reinstalled the OS the Computer
account is not the same as before and he can no longer access the
files that were on the other drive. I have tried several of the free
downloadable recovery packages Advanced EFS recovery and others but
have had no luck, the recovery agent displays that no user is able to
decrypt the files and the user account has not changed because the
user is in a domain. I have tried logging in as local admin, domain
admin, but still no luck. anyone know of anything I can do. and no
the user didn’t export the keys.

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Jupiter Jones [MVP] - 28 Apr 2005 05:54 GMT

Was there a Designated Recovery Agent on the domain?
If not, the data is most likely gone for good.

See the bottom of this page for ways to help prevent data loss with EFS in
the future:
http://www3.telus.net/dandemar/encrypt.htm

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Jupiter Jones [MVP]
http://www3.telus.net/dandemar
In memory of our dear friend, MVP Alex Nichol
http://www.dts-l.org

> Recently I used RIS (Remote Installation Service) to reinstall a
> clients workstation because it had been upgraded and had different
[quoted text clipped - 9 lines]
> admin, but still no luck. anyone know of anything I can do. and no
> the user didn't export the keys.

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Mouse4440 - 29 Apr 2005 15:31 GMT

"Jupiter Jones MVP" wrote:

> Was there a Designated Recovery Agent on the domain?
> If not, the data is most likely gone for good.
[quoted text clipped - 36 lines]
> abuse:
> > http://www.windowsforumz.com/eform.php?p=1177687

I’m not sure, I logged in as admin on the local machine and as the
domain admin and the windows recovery thing display no recovery agent
present. is this something that user had to setup or is an automatic
thing?

Reply to this Message

Kerry Brown - 29 Apr 2005 15:52 GMT

> "Jupiter Jones MVP" wrote:
> > Was there a Designated Recovery Agent on the domain?
[quoted text clipped - 42 lines]
> present. is this something that user had to setup or is an automatic
> thing?

With XP you have to setup the recovery agent. Win2k worked differently. If
he was logged on locally when he encrypted the files you are probably out of
luck. If he was logged on as a domain user you will have to figure out if
there is a recovery agent and who it is. Export the recovery key and import
it on the machine with the files on it. You may also have to take ownership
of the files on the USB drive first.

http://support.microsoft.com/default.aspx?scid=kb;en-us;887414

http://www.microsoft.com/resources/documentation/Windows/XP/all/reskit/en-us/Def
ault.asp?url=/resources/documentation/windows/xp/all/reskit/en-us/prnb_efs_lnfx.
asp

Kerry

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Mouse4440 - 29 Apr 2005 17:24 GMT

"kerry15" wrote:

> > "Jupiter Jones MVP" wrote:
>  > > Was there a Designated Recovery Agent on the domain?
[quoted text clipped - 97 lines]
>
> Kerry

He was a domain user but the key was on the system partition and the
data is on another drive, the system partition that had the keys was
deleted with the install of Win XP. I logged in as the user and the
recovery agent displays no recovery agent present, likewise for the
local admin and domain admin. I have not taken ownership though.
would I need to do that for the recovery agent.

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Kerry Brown - 29 Apr 2005 17:40 GMT

> "kerry15" wrote:
> > > "Jupiter Jones MVP" wrote:
[quoted text clipped - 105 lines]
> local admin and domain admin. I have not taken ownership though.
> would I need to do that for the recovery agent.

You have to figure out who the DRA is (see my previous links), export their
private certificate and key, then import the certificate and key on the
computer that you are using to decrypt the files. It is common practice to
only use certain secure computers for EFS recovery so that the key cannot be
taken away and data unencrypted off site. If this is the case you would have
to have the files on the recovery computer. You may or may not have to take
ownership first but it wouldn't hurt to do so. EFS can be very tricky. From
what you have described his data is probably gone. You should investigate
the links in my last post and either restrict users from using EFS via group
policy or setup a DRA and store the certificate and key in a safe place. If
you don't this may cause you grief again in the future.

Kerry

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