Is it poosible to block and logg specific user

Hi
I it possible to block a user by his “S-1-5-**-****” number, and if so can I logg activity from same user?

What’s happened… Dual boot between XP pro and Vista, vista removed and only xppro left as op.
Vista left behind a folder “Old_Bo” that could not be erased by admin unless safe boot/admin and change ownership from file level to root.

If this user was active (S-1-5-80-***), where is it now?? I can’t find it in the registry so I want to block and logg all activity, if any at all.

Thx in adv. (:WAV)

Well, it seems that there is no answer to the q.
Anyhow, this SID are vistas new “TrustedInstaller” service that take ownership over many things and processes in vista. It’s one of the new parts in security thinking by Redmond.
Problem solved when I finally got this folder cleaned out.