HELP!!! I Locked Myself Out of MY COMPUTER!!!

I have windows xp business edition
It has been only me using this computer since the day I got it.
But circumstances changed and now I need to SHARE it with my mother.
I didn't want her seeing my files so I thought I would make her a separate user account
But because I never made an account before....I had to designate her account as the administrator account
Then when I restarted the computer...
MY USER ACCOUNT WAS GONE!!!
And I guess cuz I never added another account before....that windows considered my mother's account to be the only one ...which is brand new with none of my programs and settings and files.
So then I went to user accounts in control panel and set her account to LIMITED and the other account (that was password protected) to Administrator.
But THAT account NEVER shows up AT ALL!! And it wasn't the same account as I was using before I made my mother's account.
This was some kind of "ghost" account that always showed up in the control panel but NEVER on the log in screen
So now I can't access this "ghost" account!!
And the ONLY Login Name SHOWING is my mother's account with is NOW SET TO LIMITED!!!
So I can't do shit!! I can't add another account...I can't change ANY settings!!! Because it's NOT the administrator account!!
So since that is the ONLY user name coming up on the LOG IN ... I'm totally screwed!!!
Now I know my "original user" account can't be totally gone cuz the same amount of hard drive space is still being used. But why can't I find it???
Why is my mother's LIMITED account the ONLY ONE SHOWING ON LOG IN???

PLEASE PLEASE HELP ME!!!

I spent a YEAR getting my "old account" to just the way I liked it and it has all my files and settings intact. Being on mother's account is just like it is when you first reinstall windows and everything is reset!! I HATE IT!!!

What did I do??
How did I LOCK MYSELF OUT of MY OWN COMPUTER???

ARGHH!!!!

 

Thank YOU so much!!!
Now will I be able to regain access to the original user account that refuses to show up now that I made my mom's account??

Oh and I am a bit confused by one thing you said when talking about booting in safe mode and to make a new account ....

add one (but no named admin) with admin priviledges

What do you mean? Make a new account but not make it an admin account?

 

Oh I understand! Thank you!!

Now how do I reboot in safe mode?? Hit the F2 key while it's loading up?

 

Ok! Awesome!!

So now I fixed the user names.

But how do I get the original user name to show up? That is the one that had all my settings and downloads and scans. I need THAT account to work but it only shows up in safe mode. Is there a way to change that???

Or am I just screwed??

It doesn't let me delete the other accounts when I am safe mode. Because I tried to bypass this problem by activating the guest account and then trying to delete all the other accounts so that the original admin acount would show up but it won't let me delete the others...

Is there a way to fix this??

Thanks for all your FAST help!! I appreciate it immensely!!

 

Ok....I did what you said. And I made the two new accounts. They have admin privileges. But I still can't find the orginal account ...the one that says ADMINISTRATOR unless I boot up in safe mode but then hardly anything works so all my old settings are still unavailable to me. Is there any way to get into that account without having to boot into safe mode first??