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Why are there so many user accounts on my machine?

Why are there SO MANY (9!) user accounts on my PC? I’m the only one who uses
it or has access to it. I recently did a re-install of Windows XP and SP2 & SP3
(because of a virus). Many of these user accounts have duplicate folders, all
full of files. Is this using disk space? How do I delete unnecessary, redundant
user accounts without adversely affecting the PC? I have Googled both your website, your partners’ websites, and the web in general and have not found the
answer. What are the minimum number of user accounts?

As with so many things, the answer is: it depends.

To begin with, Windows has a slightly different idea of what it means to be
a “user” than you and I do.

Add to that the various and sundry software packages that you might have
installed and the number of user accounts can get … interesting.

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A user is a user is a …

You and I naturally think of a user as a person who uses the computer. In
most cases, there’s only one user and it’s you … or me.

The separate “Administrator” user account is something that I think most
people at least somewhat understand as simply a different login that might have
more privileges associated with it than our normal account.

Typically, it’s the same real-life user; we might choose to login to our
machines as the Administrator or with an account that has administrator rights,
but to Windows, it’s actually a different “user”.

So, Administrator (which is often hidden) and our own login account – we
probably understand why they’re there.

Then it gets … interesting.

Some user accounts in Windows XP

Additional Windows accounts

One account that you may see from time to time is called the “Guest” account.

Ultimately, it’s an account created to allow individuals or other computers
who don’t have accounts on your machine to do things with your machine
anyway.

For example, you might make your printer or a network share available on your
local network and allow anyone who can connect to it to access it. The
Guest account is one way to do that.

More often than not, the Guest account is disabled. Even with restrictive
security settings in place, it can be more of a security hassle than it’s
worth.

Additional software accounts

Occasionally, software that’s installed on your machine needs to “look like”
a computer user. It’s one way that software can sometimes be granted privileges
greater than what your login account might have without granting the software
full, no-holds-barred administrative access.

The .NET framework seemed to be particularly prone to adding user accounts
for various reasons, although in later versions, less so (or perhaps Windows 7 has
done a better job of isolating them in a not-as-visible way).

Another somewhat common scenario is backup software. Backup software often
needs lower level access than your typical login account. As a result, when
setup is run, it creates an additional user account for the backup software.
The setup, typically run with full administrative access, creates a new user
account that (as I said before) has fewer privileges than Administrator, but
perhaps a couple of additional privileges than a limited user account might
have.

The backup software then logs in using its own account when it performs
its actions.

It’s all about security

It’s really all about security and making sure that the various software
packages have the appropriate level of access; they can do the things that they need to in order to do their job without being granted access to things that they don’t.

The concept of “user” is really a concept of “account,” and thus, accounts
are generated automatically that may never ever be used by a real human user
directly.

Booting users

You asked how to delete unnecessary user accounts and for that, I have a
simple answer:

Don’t.

The key is really understanding which ones are truly unnecessary and for
that there’s no simple answer. Sure, if there’s an XYZ User that appeared
after installing XYZ Backup, then it’s probably safe to delete that user after
uninstalling the backup program. But that’s about as good as it gets.

In most cases, it’s not at all clear which are unnecessary, mostly because in
most cases, none of them are. Yes, each might take up a little disk space (often
not as much as you might think), but even if they do, that account and that
disk space is very likely part of what’s required and used to provide a service
on your machine.

Deleting that user could easily cause something that you care about to fail.

Thus, I recommend not deleting them at all; the only caveat being to make
sure that you are keeping your computer properly secure and malware free.
Malware could, of course, create user accounts to hide or otherwise obscure
what it’s up to.

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5 comments on “Why are there so many user accounts on my machine?”

  1. The obvious-to-me question, Leo, is “Did the virus create a user account which is now a gateway for malware or worse?” Is there any way to determine that?

    It’s certainly possible, but difficult to know by just looking. That’s why I stress using good anti-malware tools and keeping them up to date.

    Leo
    07-May-2012
    Reply
  2. Regarding the enquirer’s comment about ‘duplicate folders, all full of files’ is this, in fact, so? I have, always, assumed that there is one or, possibly, two copies of a file and that there are umpteen ‘indexes’, each one associated with a User, which point to the whereabouts of the relevant files on the HD. And the same applies to the apparent multiplicity of files in various parts of a computer such as in Documents and Settings and similar collections of folders and files.
    If I am correct, the only increase in disk space associated with many User Accounts is from the various ‘indexes’ or ‘contents list’ which, I presume, are part of the Registry.
    Would it be worth your elaborating on this matter sometime, Leo, so those of us who like to know how a computer works can have a clearer understanding of what goes on under the bonnet? As I am sure you realise, things were a lot simpler in Win9x and earlier!

    Reply
  3. I’ve come across instances where user profiles have not been able to load for whatever reason so Windows creates a temporary profile. So you could end up with many ‘user profile’ folders named with variations of your username e.g.
    youusername
    yourusername.000
    yourusername.001
    yourusername.computername

    Reply
  4. One thing I learned long ago with Windows. If it works, don’t mess with it. I used to go through the files in every nook & cranny to see what was there, if it was needed, and if I could delete it. Big mistake. The more I learned, the more confused I got. It’s amazing that it works at all [most times].

    Also, I learned to resist the urge to peek into the event viewer. Just looking at it I would swear my PC was on the verge of imploding.

    Reply
  5. One could backup then delete a user account. If nothing get broken, you’re good to go. If it’s broke, backup.

    Reply

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