is one of the oldest on the internet sea princess, and almost everyone has seen it at some point - it was very prevalent several years ago.
The best advice I can give is that you totally ignore any mail that tells you something will wipe your hard drive, or erase your data, or do anything bad to your computer whatsoever. Some of these hoaxes say that a warning has come from Microsoft, or the pentagon, or an eminent professor at Harvard, or one of the big anti-virus software companies.
None of these sources would ever issue such a warning via email, and under no circumstances should you pass the message on to everyone in your address book - that is precisely what the originator of the hoax wants you to do.
Just delete any such emails and carry on with your life. By all means mention such things here, in the forum, but leave it at that.