Hidden User Account (Win 2008 32 Bit Standard)

hi guys, can anyone got a remedy for this problem.. i execute the command net user at the command prompt.. then i noticed a user name which i cannot find in the user active directory nor in the user accounts on control panel.. when i tried to delete in command prompt using net username /delete unable to delete it says that "built-in accounts cannot delete "..
just recently the norton able to detect some virus..but able to remove it.. but now no matter how i tried to do a rescan norton reports no virus anymore.. but i'm facing this scenario in which there is hidden user account.. any work around on this? thank you.

 

hi, to elaborate further on my question.. i execute a "net user" at command prompt then compare the result at AD list.. but there's one user that is listed on the command prompt but is not listed on the Users Active Directory.. is there a way to check which domain or computer that particular is connected to? thank you.. any ideas is greatly appreciated..