Was just repairing a clients Windows machine yesterday. The spyware infection reminded me more of a cancer than anything else. If you don't get every last bit you'll get reinfected. The worst part is this malicious code puts itself in the registry, and with the ability to hide registry entries and to hide files from the file managers, cleaning may not be possible unless you know how to unhide this stuff. While the same can be done with Linux by replacing certain system tools, there is no registry to deal with. This is itself a great boost to cleaning an infected Linux system. There is no need to scour a registry looking for cryptic keys, that have no relationship to the infecting program(s). This is a great asset, since this particular system had been infected since July! Hence even were he to have kept backups of the registry, it is unlikely he'd still have a pre-infection copy of the registry. While it is a nice idea to have a central database where one can configure everything on the system, it was an extremely bad idea to make it so cryptic and accessible for abuse.
Anyway that's my thought for the day. Avoid the cancer that Windows has become, use Linux.
P.S. This one spyware program made over 200 entries in the registry, had over 1600 copies of bits of itself hidden in various locations (each of which were enough to spawn a new infection), and was running about 40 copies of itself in memory (thus maxing out the CPU whenever the infected user logged in).
Brian JD