The Machine SID Duplication Myth and Why Sysprep Matters Marks Blog. On November 3 2. 00. Sysinternals retired New. SID, a utility that changes a computers machine Security Identifier machine SID. I wrote New. SID in 1. NTSID because the only tool available at the time for changing machine SIDs was the Microsoft Sysprep tool, and Sysprep doesnt support changing the SIDs of computers that have applications installed. A machine SID is a unique identifier generated by Windows Setup that Windows uses as the basis for the SIDs for administrator defined local accounts and groups. After a user logs on to a system, they are represented by their account and group SIDs with respect to object authorization permissions checks. If two machines have the same machine SID, then accounts or groups on those systems might have the same SID. Its therefore obvious that having multiple computers with the same machine SID on a network poses a security risk, right At least thats been the conventional wisdom. The reason that I began considering New. SID for retirement is that, although people generally reported success with it on Windows Vista, I hadnt fully tested it myself and I got occasional reports that some Windows component would fail after New. Ms Office 2003 Sp3 Dk Books' title='Ms Office 2003 Sp3 Dk Books' />SID was used. When I set out to look into the reports I took a step back to understand how duplicate SIDs could cause problems, a belief that I had taken on faith like everyone else. The more I thought about it, the more I became convinced that machine SID duplication having multiple computers with the same machine SID doesnt pose any problem, security or otherwise. I took my conclusion to the Windows security and deployment teams and no one could come up with a scenario where two systems with the same machine SID, whether in a Workgroup or a Domain, would cause an issue. At that point the decision to retire New. SID became obvious. I realize that the news that its okay to have duplicate machine SIDs comes as a surprise to many, especially since changing SIDs on imaged systems has been a fundamental principle of image deployment since Windows NTs inception. This blog post debunks the myth with facts by first describing the machine SID, explaining how Windows uses SIDs, and then showing that with one exception Windows never exposes a machine SID outside its computer, proving that its okay to have systems with the same machine SID. Hqku4N0wbo/Tcmyci4s15I/AAAAAAAAADk/uVorD7X3Hf8/w1200-h630-p-k-no-nu/e6f9352b84ae97b2d06444c745106c03.png' alt='Ms Office 2003 Sp3 Dk Books' title='Ms Office 2003 Sp3 Dk Books' />Note that Sysprep resets other machine specific state that, if duplicated, can cause problems for certain applications like Windows Server Update Services WSUS, so MIcrosofts support policy will still require cloned systems to be made unique with Sysprep. SIDs. Windows uses SIDs to represent not just machines, but all security principals. Security principals include machines, domain computer accounts, users and security groups. Names are simply user friendly representations for SIDs, allowing you to rename an account and not have to update access control lists ACLs that reference the account to reflect the change. A SID is a variable length numeric value that consists of a structure revision number, a 4. RID values. The authority value identifies the agent that issued the SID, and this agent is typically a Windows local system or a domain. Ms Office 2003 Sp3 Dk Books' title='Ms Office 2003 Sp3 Dk Books' />Subauthority values identify trustees relative to the issuing authority, and RIDs are simply a way for Windows to create unique SIDs based on a common base SID. You can use the Sysinternals Ps. Get. Sid tool to view a machines SID by running it with no command line arguments Here, the revision number is 1, the authority is 5, and there are four subauthority values. At one point during the design of Windows NT, the machine SID might have been used for network identification, so in order to assure uniqueness, the SID that Setup generates has one fixed subauthority value 2. S 1 5 2. 1 in the output. Even before you create the first user account on a system, Windows defines several built in users and groups, including the Administrator and Guest accounts. Instead of generating new random SIDs for these accounts, Windows ensures their uniqueness by simply appending a per account unique number, called a Relative Identifier RID, to the machine SID. The RIDs for these initial accounts are predefined, so the Administrator user always has a RID of 5. After installation, Windows assigns new local user and group accounts with RIDs starting at 1. You can use Ps. Get. Sid to view the name of the account for a specified SID, and here you can see that the local SID that has a RID of 1. Abby account, the name of the administrator account Windows prompted me to name during setup In addition to these dynamically created SIDs, Windows defines a number of accounts that always have predefined SIDs, not just RIDs. One example is the Everyone group, which has the SID S 1 1 0 on every Windows system Another example, is the Local System account System, which is the account in which several system processes like Session Manager Smss. Service Control Manager Services. Winlogon Winlogon. SIDs and Access Control Lists. When an account logs on to a Windows system, the Local Security Authority Subsystem LSASS Lsass. A token is a data structure the Windows kernel defines to represent the account and it contains the accounts SID, the SIDs of the groups that the account belongs to at the time it authenticated, and the security privileges assigned to the account and the groups. When the last token that references a logon session is deleted, LSASS deletes the logon session and the user is considered logged off. Here you can see my interactive logon session, displayed with the Sysinternals Logon. Sessions utility And here you can see a token Lsass has created for the session in Process Explorers handle view. Note that number following the account name, 7fdee, matches the logon session ID shown by Logon. Minecraft Ps3 Edition Worlds Download Mp3 on this page. Sessions By default, processes inherit a copy of their parent processs token. Every process running in my interactive session, for example, has a copy of the token that they inherited originally from the Userinit. Winlogon creates as the first of any interactive logon. You can view the contents of a processs token by double clicking on the process in Process Explorer and switching to the Security page of the process properties dialog When one of my processes opens an operating system object, like a file or registry key, the security subsystem executes a permission check that evaluates entries in the objects access control list ACL that reference a SID included in the processs token. A similar check happens for remote logon sessions, which are the kind created by a net use of a remote computers share. To successfully connect to a share you must authenticate to the remote system with an account known to that system. If the computer is part of a Workgroup, then the credentials you specify must be for a local account on the remote system for a Domain joined system, the credentials can be for a remote systems local account or a Domain account. When you access a file on the share, the file server driver on that system uses the token from the logon session for the permission check, leveraging a mechanism called impersonation. SID Duplication. The Microsoft supported way to create a Windows installation thats ready for deployment to a group of computers is to install Windows on a reference computer and prepare the system for cloning by running the Sysprep tool. On November 3 2009, Sysinternals retired NewSID, a utility that changes a computers machine Security Identifier machine SID. I wrote NewSID in 1997 its. Tell me about the issue and Ill help you find the solution you need.