That's because your operating system has a flaw that allows an attacker to hack into your computer and delete files!
The back reads:
- Update your computer software, especially the operating system, Internet browser and email software with software patches once they become available
- Use the automatic feature from the software company to keep abreast of software patches.
The sender writes that this is a "Chew On It" comic strip drawn by a Singaporean and is postmarked in 2007.