Some time ago, I was in the situation to set up a new computer with a Windows XP 64 CD. Well it doesn’t matter that it was 64bit.  However, I always create a separate partitions for Windows XP. And because user profiles tend to get big, I moved a new user to a second partition. [...]

SID is the short form of Security Identifier. It is used to uniquely name a user (like Alice or Bob), a group (like Users or Administrators) or a system account (like SYSTEM or Network Service). Important to understand is that not only human users get a SID but also system parts like the System or [...]