QUESTION: I've been told that I shouldn't have more than one antivirus program running on my PC. Can I use both McAfee and Microsoft Anti-Spyware (or another spyware application), for example? I want to be extra safe online, and I know that security suites are often good in some areas but not in all. Is there a list that will tell me what I can and can't use together?
ANSWER: You're right, having more than one security application trying to do the same thing can cause a conflict, as well as hog system resources. Many security programs span multiple areas, with much overlap between their firewall, antivirus and antispyware software. Antispyware and antivirus differ, but the lines are blurring, and many antivirus programs detect and clean what would traditionally be considered spyware.
It's not advisable to run the Anti-Spyware component of McAfee alongside Microsoft Antispyware, but if it's only McAfee Anti-Virus that you're running then there shouldn't be a problem.
There's no definitive answer as to what can run with what, aside from saying you shouldn't have multiple programs doing the same thing. Antivirus should always be running; it's also advisable to use a real-time antispyware to prevent infection. You can install extra antispyware programs that run passively when you choose. These will scan your files in the background, removing any infestations that are lying dormant or have evaded previous security software.
The former has a live component to protect your Registry from system changes and block bad pages in web browsers. Ad-Aware, meanwhile, can be run on command to search through your Registry and files to eliminate hidden bugs.
For a free all-in-one solution, Microsoft's Security Essentials suite should fit the bill. Note that free solutions often won't offer paid-for benefits such as automatic updates, custom alerts and up-to-the-minute malware signatures.