Hamachi will allow you to establish secure direct connections to PC's that are not accessible otherwise due to the restrictions in network setup.
LanTopolog is an application that provides physical network topology discovery, visualization and monitoring.
ChrisPC DNS Switch
NetSetMan is a network settings manager which can easily switch between 6 different, visually structured profiles. Pre-prescribing network settings, you no longer have to write them again when you change your network connection (for example, when you connect your home computer at work, in cafes, or frequent switching between providers).
LanHelper can scan network at high speed and it can even detect writable or read-only shared folders with the powerful and special engine. Boot (wake up) or shut down or lock your PCs.
Q-Dir is a free file manager with tabbed interface and broad functionality, unlike the built-in Windows Explorer . In the windows of Q-Dir, you can open folders, network drives, FTP-server, zip and rar archives, as well as move and copy files between directories open.
Media Player Classic Home Cinema
Media Player Classic Home Cinema (MPC HC) - is an extremely light-weight media player for Windows. It looks just like Windows Media Player v6.
CCleaner(formerly Crap Cleaner) is a freeware system optimization and privacy tool. It removes unused and temporary files from your system - allowing Windows to run faster, more efficiently and giving you more hard disk space.
J. River Media Center
J. River Media Center (formerly Media Jukebox) provides an easy, efficient way to collect, organize, and play music and other media files on your PC.
Sysinternals Suite is a full-featured pack of system utilities that cover a wide range of functions and needs and which are especially addressed at expert users and system administrators.