- Agent Ransack File search tool, supports advanced queries (including date/time modified ranges) (freeware)
- BGInfo - Creates desktop wallpaper showing system information, and can be run at logon to update it.
- Bootable USB Drives - Creation, etc.
- BrowsingHistoryView - Great free tool from Nirsoft for viewing users' browsing history. If you need to know what sites someone's been accessing, this is absolutely the best way. You can view any or all users' history from all browsers, and spit-out html reports.
- Runs as portable executable. Download at http://www.nirsoft.net/utils/browsing_history_view.html
- Orca - Free tool for viewing .msi contents and creating/editing .mst transform files.
- PowerGUI - Great tool, best way to browse AD, WSUS, etc. Fast, good queries.
- Regshot - Lets you take before and after snapshots of the registry and then compares them and lists changes. Useful for seeing what registry key corresponds to an application setting, etc.
- RSAT - Remote Server Administration Tools, an MS package for workstations containing MMC snap-ins like "Active Directory Users and Computers" (ie. you can view/edit Active Directory without remoting into a server).