Remote-control offerings aren't exactly thin on the ground – XP Pro has one as standard, and there's always free VNC (virtual network computing). But these are one-to-one tools, not perfectly suited to the larger task of administering and supporting networks. For this, you need a product along the lines of NSM (NetSupport Manager).
NSM 9.1 offers a list of support features. As well as remote control, you get file transfer, chat and a hardware/software inventory. The Monitor mode allows you to shrink desktops down to thumbnail views so you can keep an eye on a number of workstations at once. Or you can 'channel surf', displaying each desktop in turn. It's also possible to share control of a remote desktop, so you can walk a user through a problematic task, and there's a record/playback feature that can be useful as a teaching tool.
Remote web access is available via the bundled ActiveX controls, so you can remotely control a client over the internet direct from a browser. NSM 9.1 works best with Windows clients but more limited support for Pocket PC, Linux and Mac is available.
Reassuringly, NSM 9.1 worked right out of the box. Installation is a snap – you install the whole package on the 'monitoring' PC and just the client on the ones to be monitored. This can be done remotely via a 'deploy' feature.
The well-thought-out Explorer-like interface makes using NSM 9.1 a very intuitive experience, and for most tasks we found no need to refer to the extensive manual. This is a major plus, considering the program's wide-ranging and complex functionality.