true admin account disappeared

[AlexNeedsHelp]

I had been using the true admin account to do my everyday work (now i know i shouldn't have) and lastnight i decided to change my SID using the NewSid program.. the first time around it just sat there for a couple hours not managing anything but to open a new account.. the ASP.net machine account... since i had no idea what it was or what it did i chose to delete it (again, now i know i shouldn't have).. then i tried the NewSid again, only this time it worked.. it changed everything, and rebooted the system.. only to find out I only had my guest account, my admin and regular account are not showing up.. though my hard drive is still intact, and I can still see my admin and regular account folders.. just cant access them.. any help is highly appreciated, thanks for your time!