None of Symantec's product range is relevant to Macs and, as you have discovered, will often damage your machine's performance. For most practical purposes, you have been immunised against viruses, worms, etc by buying a Mac and, while the PC world lives in justified fear of disaster (whether from hackers or Microsoft itself through its spyware) Mac users can take a more laid back view of the world. While the act of joining your machine to the web will always have an element of danger about it, downloading the security patches from Apple on a regular basis will meet all the everyday forms of attack and then some. Save your money on antivirus products and enjoy the sunshine in your part of the world. If your Jaguar acts up, try www.macattorney.com/tutorial.html as a good source of helpful tips to put things right.