Here's a rant that should strike a few chords with regular geeks out there. The number of PC and Mac applications which state in their installation instructions: "Make sure you do the following before you install the software:
Turn off any virus-protection and security software that you may have installed on your computer." - This is from installing Final Cut Express on a MacBook by the way but I've seen plenty of other examples on a PC.
I can understand why the developers state this: it's because anti-virus and firewall software might possibly get in the way of the bludgeoning installer that the developer has bodged together. Look, let's get one thing straight: you should NEVER turn off your firewall or anti-virus, unless you REALLY know what you're doing. For example, my router has a built-in firewall and I know it's turned on, but most users wouldn't know this and it's a really bad idea telling them to 'make sure' to turn off their security just to install an application. An unprotected Windows desktop will be filled with malware worms within a minute or two of being online.
The right solution is for the developer to test their installers on systems with various security solutions installed and then work round any problems. Risking the safety of users is just lazy, lazy, lazy.