TeamViewer (installed version) can be set to start prior to the Windows login screen. It even allows a remote user to reboot the host PC into Safe Mode and reconnect. This is a fantastic feature for anyone doing remote help desk support.
Video performance was very good with just a slightly discernable lag in screen refreshes. One feature that I really like is its ability to handle multiple displays on the host. A remote user can choose which monitor to view, or they can view both at once. However, if the remote monitors are at a high resolution, the view is too small to be usable. I also like that once connected, I can choose to "switch sides" with my partner. This means that one user can initiate the connection, then pass control over their desktop to the second user later in the session.
Remote printing is supported a little differently in TeamViewer. Unlike Remote Desktop, TeamViewer doesn't redirect print jobs to the remote client. Instead, you must turn on the VPN in the TeamViewer agent at each end of the connection, then map a printer on the host computer to a shared printer on the remote device. It's a bit of a kludge and not the easiest task for nontechnical users.
TeamViewer is available in commercial versions that add more features, but at a substantial cost. The free noncommercial version is a good choice for basic remote access, but if you need to print remotely, other tools simplify the process.
VNCInfoWorld's Free RAS score: Good
The hugely popular VNC family of utilities is virtually synonymous with remote access. There are three major versions of VNC: RealVNC, TightVNC, and UltraVNC. There's also a popular version for the Mac called Chicken of the VNC. Among them, RealVNC is by far the most mature, but only in its paid incarnation. RealVNC, TightVNC, and UltraVNC all support Windows hosts and clients and provide browser-based access via Java, but none of the free releases provide remote printing. Performance is on par with the other remote access tools listed here, and the Java version is no exception. VNC is not as firewall friendly as Gbridge, LogMeIn, and TeamViewer, requiring a specific port to be forwarded to each target host.
Installation of VNC is quick and easy on Windows hosts up to Windows XP and Windows Server 2003, including 32- and 64-bit versions. TightVNC is available in a beta version for Vista and Windows 7, while support for these platforms comes via the paid version of RealVNC ($30). After you've installed the host and client software, your network admin will have to open a port in the firewall and point it at the VNC host before a remote user can connect. As with Remote Desktop, a different port must be used for each additional host.
Remote clients will have to connect to either a fully qualified URL (such as vnc.mydomain.com) or the external IP address of the firewall. It's not as elegant as logging into a Website and clicking your host PC out of a list of available devices, as you do with LogMeIn, but it works. It just requires a little more coordination between IT and the remote users.
None of the free versions of VNC support remote printing, but the paid version of RealVNC does. TightVNC and UltraVNC both allow file transfers between host and remote client as part of the free package, while this too is a paid feature in RealVNC.