User Accounts Corrupted

[Note: I posted this in vista.general, before I noticed this board]
Hello,

It looks like I have one or more corrupted user accounts on my home machine,
which is running Vista Home Premium SP1.

Background:

* Purchased Compaq F572US laptop w/ Vista Home Premium pre-installed (this
was some time ago).
* I believe there was a default account created named Owner.
* I created two additional accounts, abc and xyz. All three accounts were
admins.
* I tried to delete Owner, but instead have wound up with some bizarre
incestuous merger of abc and Owner, such that neither one is completely
functional.
* Symptoms (unless otherwise indicated, when logged in as abc):
- At bootup, I am presented with only two account options for login: abc,
and xyz, but not Owner
- Using Control Panel>User Accounts>Manage Accounts I see 4 accounts: abc,
xyz, Guest, and ASP.NET Machine Account...but *not* Owner
- However, a C:\Users\Owner folder exists, but I cannot delete it
- If I create a file and try to save it, the Save File window contains,on
the left,
-Recent Files
-Desktop
-abc
-Computer
-Network
with the contents of abc's Documents folder to the right.
However, if I select "abc" from the left-hand side, I am navigated to
C:Users\Owner, not C:\Users\abc.
- Much the same thing happens if I open My Computer from a desktop shortcut.
In the folders pane at the left appears
Desktop
abc
Public
Computer
<various drives>
Network
Control Panel
Recycle Bin
If I click the 'abc' icon, I am taken to C:\Users\Owner, whereas if I
navigate down the "Computer" path to C:\Users\abc, I reach the correct
destination folder
- (Again, still logged in as abc), if I click the Users tab on Task Manager
the only user that shows up is Owner, not abc. And of course if I click the
Logoff button at this point, I am logged off--even though I logged in as abc.

So I have a mess on my hands and no clue how to repair it, given the fact
that Owner doesn't even show up as an account for me to manage. All my REAL
data is in C:\Users\abc\Documents. I don't care which account prevails in
this little techno-throwdown, as long as a) I don't lose any data and b) I
get consistent behavior in navigation.

Side note: I have McAfee Security Center installed (ISP freebie). It has a
backup/restore feature. If I select this feature, the universe of files
displayed for potential backup is that of Owner not abc.

Thank you. Peter.