This small document contains some advice on how to make your PC more secure. Be aware that the complete security story, if there is such a thing, would probably span several books. I guess you have better things to do than read a bunch of techie books, and that is why I prepared this rather short text. Some understanding of security is, after all, far better than no understanding at all, so please read on. Regularly There's no such thing as bug-free software.
Programmers are people, and people make mistakes, all the time.
Security holes in programs are discovered every single day. There are mailing lists on the Net where advanced users and software developers participate. A patch is a small piece of program that eliminates the bug, thus tightening the security hole. You probably don't read such mailing lists and download and install the patches that become available. These are the taggers of the Net.