NewSID is a SysInternals (now owned by Microsoft) utility that changes a computer’s SID. It first generates a random SID for the computer, and proceeds to update instances of the existing computer SID it finds in the Registry and in file security descriptors, replacing occurrences with the new SID. NewSID requires administrative privileges to run. It has two functions: changing the SID, and changing the computer name.
Please note that Microsoft does not support changing the workstation SID using NewSID. Their official support policy requires changing the SID using sysprep. For more information on their policy, see KB 314828.
