I'll also heartily recommend AVG, especially for older machines (I still run Windows 98 on my desktop). I have Norton on my laptop, but on my desktop Norton absolutely refused to connect to the update server after a few years so I junked it. I then tried Panda anti-virus and it was even worse - it interfered with my games as well as my computer shutting down properly. I then switched to AVG and while its menu system is kind of primitive/unintuitive, it works flawlessly. You just install it and never worry about it again. You can buy a two-year subscription for a good price. As for spyware, every once in a while I run Lavasoft Ad-Aware. A trojan crippled my desktop once, so take it from me you can never be too protected. I wouldn't be surprised if the anti-virus companies themselves are involved in distributing viruses to keep themselves in business...