It seems that Windows Live OneCare fails to play well with other security solutions. As a general rule it is ill advised to run security products simultaneously on the same machine. The fact of the matter is that antiviruses not only fail to coexist, but also interfere with one another to the point where the Windows operating system's functionality is depreciated completely. It seems that OneCare takes this rule literally, and fails to integrate with additional security solutions, no matter their actual functionality.

In this regard, McAfee reported that OneCare had been flagging McAfee SiteAdvisor as an interfering program. "Microsoft's OneCare team issued an update on January 31, 2008 that resulted in SiteAdvisor users receiving a Microsoft warning message recommending that SiteAdvisor be removed due to interference with OneCare. SiteAdvisor doesn't interfere with OneCare in any way; we communicated this to Microsoft and they've begun to resolve the issue," stated McAfee research analyst Shane Keats.

Keats has advised users that the issue is entirely related to a glitch in OneCare and that there is no need for end users to disable either SiteAdvisor or Microsoft's antivirus. According to Keats, the two solutions coexist with no problems on the same desktop. The Redmond company will deal with the problem later this month, but until then the users will simply have to ignore the faulty alert messages from OneCare.

"As of February 21st, new installations of OneCare will not message against SiteAdvisor. However, existing users of OneCare will continue to receive these messages until sometime in the spring, when Microsoft says it will fix OneCare installations made prior to February 21. Turns out that as a general rule, Microsoft recommends running only one security application at a time because of potential performance and 'PC stability' issues. We explained to Microsoft that SiteAdvisor functionality is totally unrelated to OneCare. They agreed," Keats noted.