Quick comparison.
1) Linux doesn't have a single point of error i.e. registry. In Windows, every program keeps on messing around with some other program's registry. Application preferences are stored in separate folders in loluser's home directory.
2) When you execute a program in Linux, it can't go beyond its limits. It just can't go on and make changes in your root directory.
3) In Windows, you run a program as "loluser" why the fu(k can it make changes everywhere? If not by hook, then by crook. This is the reason why viruses in Windows can replicate easily. Not so in Linux.
4) In Linux, all the "operating system" files are owned by root. Normal users can't make change or access them. They have to run things as "root." And this is EXTREMELY strict. Not so strict in Windows. There are ways to bypass in Windows.
5) When you run a program as "loluser" it doesn't get permission to change things in the root directory i.e. the operating system directory.
6) In Linux, generally people tend to have separate partition for Operating System (known as the root partition) and separate partition for documents, application settings etc. (known as the home partition)
7) "loluser" only has free access to the files/folders which he "owns." Not so in Windows.
8) "loluser" doesn't own important OS directories like /etc et cetera, so even if he executes a linux malware, it just can't mess up with the operating system until you give it permission to i.e. execute as root. In Windows, you can somehow manage to get through.
9) "loluser" can't make changes to files owned by "loluser2" if "loluser2" hasn't given him permission to.
10) Everything is about permissions and restrictions. These things are strict in Linux and in Windows, they're a joke.
11) Phenomenon of "ownership" of files is not at all strict in Windows. (I don't even know even if it's there or not

)
12) In Windows, an ".exe" file is an executable (defined by extension). In Linux, being executable is an attribute.
13) Last but not the least, "computer viruses" are called "viruses" because their working/metabolism depends on host just like biological viruses. Linux can't run Windows softwares, they are just harmless "junk" files. An Autorun Windows virus in your pendrive is completely harmless in Linux.
14)
Ubuntu homepage | Ubuntu - Download it, install it. Use it first and then comment instead of blatantly googling things and linking articles by "experts."
Thank you.
Edit: Everything which I have said might not be completely correct. Because I'm nothing more than an average computer user.
---------- Post added at 10:52 PM ---------- Previous post was at 10:50 PM ----------
If probability of getting infected in windows in 90% then in linux its 0.09%.
The probability of Linux running a Windows executable (including virus) is 0.00%. Windows virus files are just harmless junk files in Linux. Keep them if you want to.

---------- Post added at 10:58 PM ---------- Previous post was at 10:52 PM ----------
Think Linux is free from malware? Think again; it's been hacked. - Computerworld Blogs
Only if you run it as "root" - which no one does.