15 August 2007

Duplicate User Accounts

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On Sat, 11 Aug 2007 20:58:01 -0700, SteveS

>My laptop is from Fujitsu and it came with OmniPass software (the
>fingerprint scanner software to log in).  I saw other postings elsewhere
>about it duplicating users on the login screen.  I uninstalled the software,
>rebooted - problem fixed (no more duplicate users).  I reinstalled the
>software, rebooted, the duplicate users did not show up.  I think it stems
>from the upgrade I did from Home Premium to Ultimate and had that software

Yes; any "repair install" of XP will prompt you to create new user accounts even though you already have user accounts, and registry settings that clearly indicate these accounts are in use.

If you then enter the same name(s) as existing accounts, then new accounts are created with the same name.

Vista may avoid this conundrum, but fall into others.

Behind the scenes, the real names are not the same, because the real names are something quite different to what Windows shows you.  Messy, but key to the ability of preserving continuity while allowing you to change the account name after it's created.

Specifically, you encounter not one, nor two, but three name sets:
  - the "real" unique identifier, of the form S-n-n-nn-nnn...
  - the name of the account base folder in Users or D&S
  - the name as seen at logon on when managing users

In the case of account duplication in XP, you will have:
  - unique and unrelated S-n-n-nn-nnnn... identifiers
  - old Name and new Name.PCName account folders
  - the same name at logon and account management

The risks of deleting the wrong material should be obvious.

Public Conversations


Anonymous said...

Same thing happened to me after installing 4 updates that downloaded automatically under Windows Update. I run Vista Business, and did not reinstall OS in any way, or change versions. I have no idea what caused it, or whether the issue is superficial (just duplicate user logos on the desktop) or deeper into the system. These kind of quirks are so common that I can't keep up with them, can't deal with them. My experience with Windows over the years, is unless you devote your life to administrating your computer, constantly reinstalling the OS etc., you just have to resign yourself to operating a crippled system through it's lifetime, and then start the grim process over again, when you upgrade to a new OS, as each glitch builds on each other, and mulitply.

Chris Quirke said...

Watch this space (i.e. this comments section) as this may be a big can of worms, but for now I'd say; traet those extra accounts seriously!

There's been a recent Vista update that fixes a lot of performance issues and was to have been rolled into SP1, but was instead released early (now). It may be pushed via AU (Automatic Update) though AFAIK it's not a safety fix, so may depend on whether you set AU to swallow all recommended updates or just the security (critical) ones.

This update is known to break several settings; UI goes back to unsafe "hide things" duhfaults, and (more worrying) shell folder paths fall back to MS duhfaults on C:

I may blog this when I get a handle on it, and what the impact is. The documentation of the impact (sorry, links not to hand) didn't mention account duplication.

We can chase this here (in this comments section) much as a newsgroup or web forum, if you like; if so, you may want to do the "email alert" or RSS thing, or whatever (I haven't done RSS yet)

Chris Quirke said...

BTW: On "contantly re-installing the OS"; definitely hasn't been my mileage! Since Win95 original, I haven't had to "just" re-install Windows on any of my own systems, and rarely on the ones I build.

But you are right about effort, though - I go way beyond "click Setup.exe and wait" when I build systems, deliberately doing many things differently to improve the survivability of the installation and also to avoid system slowdown as the system (and its free disk space) is used.

Anonymous said...

Same thing happen to me for my fujitsu T4220... I had uninstall the program and the duplicate account is gone. But how do i install back the program? The program cant be found in the CD provided by fujitsu.

Chris Quirke said...

Not sure what the two Anons are seeing, especially if all (visible) user accounts are being spontaneously re-created. A recent Vista patch is documented to recreate some unwanted stuff, but in testing it in Vista32 and Vista64, it has not spawned extra user accounts.

I've only seen extra accounts spawned in three circumstances:

1) Repair installs

2) Renamed user subtrees

3) Unusable accounts

Domain issues may do this but I don't work with that.

On (3), causes include file system corruption, barfed user registry hive, and corrupted log file that is associated with the user hive.

Anon 2: What is "the program"?

Anonymous said...

i don't understand any of that really, all i know is that i have omnipass on my packard bell laptop and i have double of each account!!it's really annoying i have no idea how to get rid :( help me pleaseeee....

Chris Quirke said...

Hi Car89...

What is OmniPass?

Google(OmniPass "Packard Bell") pulls up stuff that suggests it's a fingerprint login thing.

Any reason you suspect this to be a factor with your duplicate accounts?

Else I'd guess one of three scenarios apply:

1) You did a "repair install" and did not "skip" the unwanted step of creating new user accounts, and created new ones with the same names

2) You suffered file system corruption, most likely from bad exits that may have kicked in at a time when account settings were being saved, that "broke" the old accounts (most likely their registry hives and/or associated logs) so that new temporary profiles are spawned.

Suspect (2) if settings are lost between login or Windows sessions.

3) You have had some sort of misadventure with roaming profiles and/or domain setup. Sorry; I don't deal with that, and don't have skills in that area.

kn0wfe4r said...

Same thing happened to me tonight. I just purchased a Fujitsu laptop with Vista 32 Home Edition. I setup the Omnipass software and then installed the automatic windows updates. Upon rebooting the computer after such updates I now have duplicate windows logon accounts. When I go into User Accounts in Control Panel, however, I only see one. Wonder what to do?

Anonymous said...

just as another data point - Omnipass, windows update, reboot, duplicate users. That's what happened to me.


Anonymous said...

Same thing happens on Lenovo 3000 N100. Duplicate user login after Vista update. This is after clean install (using system recovery disks) , with nothing else installed than the default software.

Anonymous said...

I am another Fujitsu laptop user who is having the same issue of duplicated user accounts. If anyone knows how this can be fixed that would be great. I can't find much info on it online.

Anonymous said...


Sorry couldn't help but notice you're having problems with duplicate accounts and omnipass. Had a customer earlier with the same problem, it mainly affects packard bell systems although it obviously can affect others. Unistalling Omnipass is one solution but it's hard to re-install it as the majority of the time it's not on the bundled media. If you look at your user accounts (on vista) then look for ASP.net limited account, this can be safely removed and shouldn't affect your system unless you're a heavy user of the .net framework.


Chris Quirke said...

Hi Redfox!

You may be referring to a slightly different issue, i.e. where software adds an extra user account to the system, so that the system then prompts you to choose which account to log into on startup.

The system may start showing the "Welcome screen" and the two accounts to choose between, or it may "remember" that you wanted to always enter your "real" account until some other circumstance, such as "just" re-installing Windows, breaks that setting.

BTW, on "just" re-installing Windows XP (via a repair install), it's worth noting recent issues with Automatic Updates.

Specifically, the repair install not only reverts patches and subsystem versions (IE, WMP etc.) as expected, but also invalidates the Automatic Update code.

So not only do you fall all the way back to an exploitable unpatched state, but you can't patch up the system again, until these issues have been troubleshot.

This re-inforces my aversion to "just wipe and rebuild" as a way of managing malware infections.

Anonymous said...

Evening Chris,

It actually had two active accounts - carbon copies, no prompts, no messages!
As for restoring the system F8 usually starts the Vista RE and F11starts the OEM RE.

Any problems that develop with Automatic update after repair install can usually be resolved via Regedit.



Chris Quirke said...

Not sure what Redfox's F8=Vista RE and F11=OEM RE refers to; presumably it's a large-OEM build where there's a reserved partition containing Recovery Environment and the OEM's destructive rebuild?

On "repair install vs. Automatic Updates"; that refers specifically to XP, not Vista. Vista doesn't have an equivalent "repair install" facility, and the issue with AU compatibility is AFAIK specific to XP also.

Yes, the cleanest fix for this XP issue is regedit-level stuff, such as manually registering a short list of .DLLs - let's search for it again...



The second link describes the .DLL registrations that could prolly be as effectively asserted via a .REG

Anonymous said...

I had a friend do an install on WinXP Pro over a pre-existing version. She is not well versed in the ins and outs so she simply chose to name her new account the same as the old one. She can no longer access the documents folder of the old account and it shows empty. Are those files gone or can I retrieve them with regedit or the like?

Anonymous said...

A friend of mine recently attempted to reinstall WinXP Pro over a pre-existing install. That went off without a hitch but without the format she chose an account name identical to the one before the install. Now it won't let her into the documents folder of the old account and it registers as 0bytes. Are the files gone or can I retrieve them somehow?

Chris Quirke said...

Hi, Altayan - don't worry about the duplicate comments, I cleaned them up in the moderating :-)

There are two issues in your case...

1) Two accounts with same name

There are three levels of names involved in user accounts:
- the "welcome screen" name
- the file system subtree name
- the unique reg-level ID

In the guts of the system, only the last matters. The directory name is carved in stone when the account is created, and will be morphed from the more visible "welcome screen" name so that it will be unique, by adding machine name and/or a "1, 2, 3..." index.

So the first step is to rename the user account(s) at the Welcome screen and Control Panel, User Accounts level, so the names are unique - then you can tell which name binds to which directory subtree within "Documents and Settings". If you skip this step, there's a serious risk of deleting the wrong stuff!

When you change the name of a user account in this way, only that level of name is changed; the directory name and the reg-level ID remain the same (forever).

Don't try to change the directory and/or reg-level ID names; that will really complicate things and you will not like the results!

2) Broken data access

This is a generic issue that should be well-covered in forums and help sites. It may be as easy as navigating within "Documents and Settings" in Windows Explorer, especially if you are using FATxx.

Complicating factors here, include:
- NTFS permissions
- sub-admin user rights
- "make my files private"
- EFS on XP Pro
These factors are designed to complicate things, as part of the much-vaunted "better security" of NTFS. If you swing that hammer, you'd better have intimate knowledge of everything it hits.

I don't bother with that stuff, thus avoiding the whole mess, and thus I have little inclination to tshoot it, sorry. But from memory, the fixes may go about "taking ownership of files" from an admin-powered user account.

If EFS is in the frame, then treat C:\SVI with care, as I suspect there may be relevant info stored there. IOW, SVI becomes more than a disposable System Restore store.

Anonymous said...

THanks very much, that gives me a jumping off point. Since I don't know exactly what she did I will have to reverse engineer a lot of the problem. It is NTFS so I will have to do more research on the issue, but I already know that the files are inaccessible in Docs and Settings. I may just stuff the drive in another machine and start digging for the files. Thanks for the help.

Chris Quirke said...

You could examine the HD from Bart or WinPE boot, or as dropped into another PC, to eyeball the subtrees in "Documents and Settings". Expect to see additional subtrees with the same account base name but with the computer name (or other unique-making appendages) er, appended.

Or you can search for a file name that is known to occur within the lost data set. Searching for all instances of Desktop.ini may be helpful.

Another tool that's a useful way to eyeball what's going on, is WinDirStat - but as this lets you see everything and delete anything, it's up to you to be careful! It's orientated towards space-busting, but you can ignore the space map and look at the item, file and space counts.

Working from a Bart boot may bypass some NTFS-level "access denied" stuff, making a long story quite a bit shorter. WinDirStat and Agent Ransack both work from Bart, as do GUI file managers A43, 2xExplorer and Savant Salamander.

Anonymous said...

Google led me to this blog. I have duplicate user accounts too, which occurred when I installed Vista SP1.

I began with a Dell XPS M1530 which shipped with Vista Ultimate on it, only a couple of weeks ago. It was set to automatic Windows Update so as far as I'm aware it was up to date.

The most popular suggestion for this type of problem is to look at the Omnipass fingerprint software. However, although I have an integrated fingerprint reader, it's running UPEK software. Nevertheless, I uninstalled the software and the device, but that didn't help: still have duplicate user accounts.


Chris Quirke said...

Hi wohz!

I haven't tested Vista SP1 yet (blush) but as I understand it, it may install more like an OS upgrade or repair install, than a regulatr SP.

I say this because folks have reportedly needed to activate after installing it, plus there have been compatibility issues with installed drivers, sometimes causing reboot loops etc.

MS addresses the latter by preceding the SP install with a patch to assess whether the install will fail in this way.

If that is the case, then the spawning of new accounts may be the same generic class of problem as in other over-old OS installation scenarios, and thus unrelated to login software such as card or fingerprint readers.

The other possible issue is when existing "machine" accounts are un-hidden, i.e. appear on the Welcoms screen (perhaps causing this screen to no longer be bypassed).

In XP, this happened with .NET or something, which spawned an extra machine account. Because there was no longer only one "user" account, XP would then start to show a choice of login accounts on the welcome screen, rather than just going straight into the one.

But then you'd have an extra account, not a duplicate account.

Finally, circumstances abound where Vista may spawn duplicate shell folders (as seen via "Users" shell folder) within the same user account. Different problem, different causes (prolly the presence of extra Desktop.ini defining unwanted locations as the duplicated shell folder).


Chris Quirke said...

Oh wohz (most recent "anonymous")...

On what to do about the duplicate: Once it exists, it will continue to do so even after you fix whatever caused it to spawned.

To clean up, I'd:
- remane it via CPanel, Accounts
- backup contents of *all* Users
- delete renamed via CP, Accounts
- say Yes on "delete all files?"

Normally I'd say "set a Restore Point before doing the account deletion" for safety, though still doing a manual backup so I can Undo.

You can do that, but as System Restore doesn't track user data (tho the same engine does this as "Previous Versions", it won't be restorable via System Restore) you can't expect SR to Undo this change in a data-preserving way.