Vista - Unable to do anything admin-wise

I was admin up until yesterday.But then when i logged on today on the start-up screen there was "Other user", I could log onto it by using my own username/password.
But i noticed my own account(The one that was admin) is now displayed as a guest??
I can't edit the registry (Unable to write to registry)
I can't make myself an admin from the control panel or using netplwiz(My account is displayed as a "Debugger" on netplwiz,but i'm unable to edit anything)
I can't system restore(System restore class not registered(0x80040154)
I can't use net user in cmd(System error 5 has occured)
The current accounts list are Mcx1,My account,ASP.Net.Which are all legit.



Anyone have a fix for this

Because you can't use net user command and return error 5 this mean you have been removed from Administrators group.I don't know it is worth to try neverless:
Try to run system in safe mode and log-in to buildin administrator account and try add your account to administrators group.If buil-in admin account not appear in safe mode (if something wrong happend with the system this is possible) try to enable buildin admin by using one of them methods:

METHOD 1
User Account Password - Change from Win RE

METHOD 2
http://www.vistax64.com/851487-post2.html
http://www.vistax64.com/331839-post10.html

METHOD 3
Tools for reseting password also have option to enable/disable accounts (for built-in admin also) for example http://home.eunet.no/pnordahl/ntpasswd/

EDIT
And one question.How did you try restore system undo? From system level or from Vista DVD?System Restore - undo
METHOD ONE from this (from Vista DVD) should help although there is ability Vista DVD can reject restore system also