Оформил: DeeCo
Автор: http://www.swissdelphicenter.ch

function OnSystemAccount(): Boolean;
 const
   cnMaxNameLen = 254;
 var
   sName: string;
   dwNameLen: DWORD;
 begin
   dwNameLen := cnMaxNameLen - 1;
   SetLength(sName, cnMaxNameLen);
   GetUserName(PChar(sName), dwNameLen);
   SetLength(sName, dwNameLen);
   if UpperCase(Trim(sName)) = 'SYSTEM' then Result := True
    else
      Result := False;
 end;