A short word on Linux security:
"Linux is secure in it's obscurity;"
This is a common misconception. Linux is not obscure; being based on the UNIX model that has been around since before DOS was a twinkle in Bill Gates eyes, the structure and functions of UNIX are hardly unknown. The infamous "Internet Worm" of 1986 was the first widely publicized threat to networked computers --they ran UNIX and the exploit took advantage of the "at" command. Since then, continuing to the present day most network servers, mission critical applications, and super computers run UNIX (many Linux).
Linux is more secure than windows for several reasons, here are a few:
First of all, at its inception Linux was designed to be a desktop version of UNIX, so it progressed from a true NOS (network operating system) to a desktop OS, carrying with it a legacy network security model of server/client-user with limited permissions. Unlike windows which progressed from a single-user desktop OS to a NOS, having to add layers of security along the way.
Secondly, Linux, being open source, might seem to invite hacks but the opposite is equally true --as fast as a hack is discovered by the community a security fix/patch is usually made available.
Finally, while I admit that Linux does require the user to be a bit more educated about system administration (there is a learning curve), we all understand that an educated user makes for better security in any OS, rather than relying on mouse clicks and eye-candy that pop up warning of a threat.