I recently upgraded my dedicated racing simulation PC, so I was forced to re-install Windows XP SP2, along with all the games. As I was downloading the no-cd patches for the various racing sims I own, I was suddenly and inexplicably deluged with popups, icons, and unwanted software installations. I got that sinking feeling: I had become the unfortunate victim of a spyware infestation.
Of course, this is completely my own fault for browsing the web using the 2004-era web browser included with a default install of Windows XP Service Pack 2. If I was thinking rationally, I would have downloaded Firefox first, or at least connected to Windows Update to get the latest patches, before venturing on to the open internet. But I figured I'd save myself that work, and just pop into a few specific web sites for a few quick downloads. Couldn't hurt, right? Let my mistake be a lesson to everyone reading this: never browse the web without the very latest version of your preferred web browser. Intentionally choosing to browse the web with a three year old browser, as I did, is an incredibly dangerous thing to do.
The consequences in this case are fairly minimal since this isn't even my secondary machine-- it's a special-purpose PC dedicated to gaming. Reinstalling the operating system is no big deal. But it's still an inconvenient timesink, and in any case, the spyware infestation has to be dealt with because it causes serious performance problems and will even interrupt gameplay with incessant popups.
The two most common sites for no-cd patches are MegaGame