There's a story behind that buyout. Russinovich had a business called Winternals, and had written NTFSDOS [1], which allowed access to NT file systems under DOS.[2] Microsoft didn't like that, because it allowed booting from a floppy, bypassing NT's security restrictions, and resetting the administrator password, copying, or modifying files. (The concept that a computer could be secure when someone had enough physical access to boot a new OS seems silly now, but back then, the opposition was script kiddies, not intelligence agencies and organized crime.) So Microsoft bought Russinovich out. Wikipedia: "Winternals was acquired by Microsoft mid-2006. Microsoft has removed any traces of NTFSDOS..."
NTFSDOS was released in the late '90s, Microsoft acquihired Russinovich in 2006. That program wasn't any more of a factor than all the other wonderful utilities he'd developed over the years. In fact, if you're looking for something Russinovich was forced to retire right after acquisition, you really should mention NewSID.exe, which was really shut down hard while in ascendance (as virtualization became commonplace).
I think MS just wanted to hire one of the best Windows hackers of all time, and they pounced as soon as they got a window of opportunity for whatever reason. Everything else was a bonus.
> Microsoft didn't like that, because it allowed booting from a floppy, bypassing NT's security restrictions, and resetting the administrator password, copying, or modifying files.
This sounds nonsensical, like folk history. You can already create a boot disk to do this using all Microsoft tools: Assuming the volume is not BitLocker'd it's pretty simple to do all of this stuff with WinPE [1], including the version that shipped in 2006, or with a Windows setup DVD. Or you could simply move the drive to a machine where you are an admin.
I am pretty sure they bought winternals because they wanted to hire MarkRuss.
You could use the recovery console to gain access to an NTFS partition and I think it was a Windows 2003 disc on Windows XP wouldn't even ask you for the administration password. You couldn't access encrypted directories, but NTFS-DOS was hardly a threat. Most Linux Live CDs could at least read NTFS.
