Windows Vista : Built in administrator account disabled - Feature or Bug

Yes WOW is now.
So here comes the Windows Vista with its enhanced UI features and tighten security.
Its beautiful its awesome to use. Vista search rocks so does the office 2007 .
IE7 is great. I dont usually use firefox now (though I use flock sometimes) 90% of the time I use IE now. Media player and media center are better than ever. Windows mail is same as before not much improved except that UI is nicer and junk mail filter. Outlook is very very improved btw.
Anyways everybody is singing these words now a days so I need not talk about this any more.

Though I like all above features still I'm furious about the so called security enhancements. Particularly about the Disabled default administrator account.
On my Vista Ulmtimate I had 2 admin account. One obviously that default admin and one of my own restricted admin. Everything was going great without any problem till the day I thought of using much hyped vista standard accounts so I demoted my account to standard user. Every thing was ok till I realized I did the biggest mistake of my OS life time. I didn't have a admin account now because that precious built in admin is disabled now. Even in safe mode I can't access that account..
I dont blame myself for the silly mistake 'coz I used to recover easily from similiar problem in XP.

LOL in my linux unix days I always had some backdoor to recover from the injury but now I'm totally scrwed up. I dont wanna reinstall my whole system. Its a big trouble for me at the moment.

Vista team did a great work over this whole new operating system. Kudos to them, but they forgot to take care of this edge case scenario which is not really an edge case..

Looking forward for the solution of this problem soon

Referred links:
http://blogs.msdn.com/windowsvistasecurity/archive/2006/08/27/windowsvistasecurity_.aspx
http://blogs.msdn.com/uac/archive/2006/08/27/727741.aspx