A guy rings tech support to report that his computer is faulty.
Tech: What's the problem?
User: There is smoke coming out of the power supply.
Tech: You'll need a new power supply.
User: No, I don't! I just need to change the startup files.
Tech: Sir, the power supply is faulty.  You'll need to replace it.
User: No way!  Someone told me that I just needed to change the startup
files and it will fix the problem!  All I need is for you to tell me
the command.
    
10 minutes later, the User is still adamant that they are right. The
tech is frustrated and fed up.
    
Tech: Sorry, Sir.  We don't normally tell our customers this, but there
is an undocumented DOS command that will fix the problem.
    
User: I knew it!
Tech: Just add the line  LOAD NOSMOKE.COM  at the end of the
CONFIG.SYS.  Let me know how it goes.
    
10 minutes later.
User: It didn't work.  The power supply is still smoking.
Tech: Well, what version of DOS are you using?
User: MS-DOS 6.22.
Tech: That's your problem there.  That version of DOS didn't come with
NOSMOKE.  Contact Microsoft and ask them for a patch that will give you
the file.  Let me know how it goes.
    
1 hour later.
User: I need a new power supply.
Tech: How did you come to that conclusion?
User: Well, I rang Microsoft and told him about what you said, and he
started asking questions about the make of power supply.
    
Tech: Then what did he say?
User: He told me that my power supply isn't compatible with NOSMOKE.

ha...ha...ha        :)