Jay wants to know if removing viruses is the same between Mac and Windows. Leo says that there's a debate that Macs are either more secure, or are a smaller target because there are fewer of them. Leo says that malware writers are going to write for the largest segment of computers. But OS X is based on Unix and that's more secure than Windows. OS X also has an administrator requirement when installing software.
There's few of them out there and the OS makes it harder to get one installed in the first place. There are some antivirus companies for Mac, and Intigo is the best, according to Leo. But at the end of the day, it's highly unlikely that he'll ever get a virus. It's more likely that Jay is dealing with a failing hard drive.