Admin rights lost

Hello, I´m royally screwed. Basicly I can´t do anything because I have no admin rights. After an accidental SID change (I know I know) I got locked out of my admin account. And since this pc has no other accounts I´m f*cked.

First of all, system restore doesn´t work because I didn´t reboot in days. Second, booting in safe mode to get to the secret-administrator account doesn´t work either because it isn´t there. Now I tried the cmd>net user administrator /active:yes but ironicly this needs administrator priviliges ofcourse. An alternative I found for this was boot in safe mode>Ctrl+shift+enter and type net user... but Ctrl+shift+enter didn’t work and running cmd normally gave me the same no-rights error.

All of this wouldn´t be a problem if I could just type in my administrator password somewhere (which I still have just to clearify) and regain acces but ofcourse since this is vista, my password is useless. Way to go!

The only place where I can type in my administrator password is F8>Repair computer, which leads me to the pre-installed vista setup. Here I can login to my administrator account which leads me to the repair options and I already tried all of those exept the complete backup one. Now the funny thing is this > http://www.jimmah.com/vista/imgs/re6.jpg should be displayed but in my case I miss the cmd option which I need for this solution> http://www.jimmah.com/vista/Administ..._of_admin.aspx

Now even though I’m sure vista is super-good-awsome enough to make this beautiful traphole on its own I still believe there might be some virus or something at work. My AVG didn’t pick up anything but any suggestions are welcome.

I’ve weaseled my way out of a lot of trapholes before but this seems to be foolproof. Before posting anything keep in my mind that I can hardly run anything, can install nothing and can’t change anything. The only possible ways I see to get out of this, is too use my admin password somewhere, hack my way past the admin prompt or maybe something with safe mode.

The only real option I have left is to reinstall my OS (if I can even manage that) but I really really don´t want to do this since the account I got locked out of contains 100 gigs of precious memories. Please I really need help.

I had somewhat similar problem like you and this tool worked - http://pogostick.net/~pnh/ntpasswd/.
You just need to enable the default "administrator" account that installs with every windows installtion and Set the "administator" password to nothing. Restart your machine and the administrator user will be now available on startup with no passwords.

Wow this looks really prommising but realisticly do you think this will solve my problem? Also I found the info on the site very hard to understand, my lack of computer knowledge is really letting me down at this point :D