If you are interested in creating a computer virus, trojan, worm, or other malicious program as revenge, payback, or as a prank for an individual or a company I suggest you re-think.
Creating a program to delete files or to cause other issues with a persons computer resolves nothing, may cause you additional issues, may cause you to be prosecuted by the law. In other words you could be fined and/or sent to prison.
Users who are interested in creating computer viruses or other programs should consider learning to program in a computer programming language. You will learn a lot more by learning one or more programming languages and you will become more qualified in getting hired at a company that designs programs. No one ever got hired by a reputable company for writing computer viruses.
If I create a good computer virus wont I become famous?
No, the only fame you will likely get is a news article and maybe a picture of you when you are handcuffed and being sent to prison. In fact if you were to write a computer virus that was effective and infected several computers or networks you would more than likely not wish to become famous at the fear of being prosecuted by the law.
I only want to write a virus to learn how they work.
You will learn a lot more about how computer programs and viruses work by learning to program then you ever will by writing and tinkering with computer viruses.
If I write a good virus I'll get hired at a security firm or antivirus company.
False, no respectable security firm or antivirus company wants to affiliated with an individual who has created a program that has infected potential customers computers. If you're interested in getting hired on at a security firm, antivirus company, or just want to get into the security field it would be much better to learn programming, become a participant in security discussions, become a beta tester, and/or attempt to find vulnerabilities in programs and operating systems and report them to the companies.
