Although this article specifically refers to XP, it also applies to pretty much any version of windows built on the NT kernel.
It’s a good overview on how virtual memory works in the kernel and why page faults aren’t necessarily indicative of low memory.
Ever have a process that won’t go away no matter what you do? You’ve kill -f <processname>‘d it and yet the PID just won’t die? I’ve seen SAV do this a fair number of times.
Why do some process stay in Task Manager after they’ve been killed? will explain why in most cases you’re relegated to a reboot to fix it.
Technet has these two gems on Active Directory Searches and Replication that make for informative reading if you have to deal with either.
MSDN has some references for the scripts that are included in the GPMC. These scripts can be used to create or backup GPOs for a domain, set permissions on GPO and many other scripting tasks.
Brage-CM is a free change tracking/management solution for system configurations.
iTunes Library Updater can sychronize your iTunes library with arbitrary directories.
VMGuru is an excellent VMWare references site, the maintainer is an author of server VMWare books
PLA looks like a fairly handy log analyis tool for PIX firewalls, for free.
Source Control HOWTO contains a good high level overview of source code management.
SetACL is a set of routines for managing Windows permissions (ACLs) from the command line, from scripts and from programs. These routines can be used from various container or interface programs. Currently there exists a command line version to be used in batch files or scripts and an ActiveX control (SetACL.ocx) which can be used from any COM-enabled language (VB, WSH scripts, …).
Chaosreader for connection statistics out of a packet capture.
Airsnare is a windows based wireless IDS, of sorts.
AntiHook monitors processes creating system wide hooks in windows.
Online multi-engine virus scanner
Ever wanted to play with Regular Expressions and not pull your hair out?