That's not a good idea. In general running more than 1 application with active protection can cause clashes and may allow infections in, rather than doubling your protection.
A general rule of thumb is never to run more than 1 antivirus, 1 firewall (exception would be a hardware-based one such as those found in routers), 1 pop-up or ad blocker, but you should have one or two antispyware applications on hand and updated, just in case.
The free ones are fine. There are some listed here: https://community.mcafee.com/thread/1996 along with some other tools.
Adaware Free is purely antispyware and is OK I suppose but personally I prefer Malwarebytes and SpywareBlaster (free).
Looks to me like Ad Aware either doesn't care or doesn't realize they are putting our computers at risk by adding anti-virus protection. There are NO options where you can choose an Ad-Aware product without anti-virus anymore. Just a Warning to anyone on the forum about this new development.
In the article below they definitely state that in their new free program (as well as the Pro pay $ program) they have added Anti-Virus protection). And there is no mention at all concerning clashes with Norton or McAfee and other anti-virus programs. (are they attempting to corner the anti-virus market?
So I guess I will have to Uninstall Ad-Aware and look for another anti spyware choice - Thank you Peter, for the long list of interesting choices.
Lavasoft's Ad-Aware Free Internet Security Adds Anti-Virus Detection to Become One-Stop Anti-Malware Tool
Gothenburg, Sweden (July 7, 2010) – Well-known anti-spyware pioneer Lavasoft today announced the global release of Ad-Aware Free Internet Security, the latest version of its flagship security product that now adds traditional anti-virus detection to its leading anti-spyware technology – offering a comprehensive first line of defense against malware and other cyber threats. In keeping with Lavasoft's vision that every computer user, regardless of economic status or geographic location, has the power to control their individual privacy and security on the Internet, Lavasoft brings an important change with this new release: Ad-Aware Free offers complete malware protection – including real-time anti-virus and anti-spyware protection, and a rootkit removal system – still completely free of charge for home users, with no strings attached. The paid version of Ad-Aware Internet Security, Ad-Aware Pro, offers multi-layered protection and more advanced control “Here at Lavasoft, it's part of our founding principle that all computer users must have the power to protect themselves online. By continuing to offer the Ad-Aware Free version and now adding anti-virus protection, we are ensuring that our users throughout the world have a one-stop product that delivers core malware protection: anti-spyware, anti-virus and anti-rootkit.