Welcome to McAfee Communities. I assume you are referring to Malwarebytes(Free). To answer your question, this particular program is designed to compliment all Anti-Virus applications, not as a replacement. You can feel confident utilizIng this Superb program.
You can locate the Download/Program below my Signature(Second Link). or for Malwarebytes(Free) HERE
Download and save to your Desktop, and close all applications/browsers and install. Do not accept the (Free) Trial or activate the (Pro) Version, as it may conflict with McAfee. The (Free) Version will suffice. After updating and running a "Threat Scan" remove and delete any items detected/Restart to entirely remove and complete the process.
All the very Best,
Message was edited by: catdaddy on 6/25/14 5:27:13 PM EDT
You should never turn off your firewall for anything and there is no need to turn off McAfee either. The only time there is a clash is if you are reinstalling McAfee, it will object to MBAM being already installed, but you can tell the installer to ignore that.
If the problem with hijacking of the browser continues you might follow the Hijackthis instructions further down the page in that link mentioned earlier (the last link in my signature below).
Moved this to Malware Discussion > Home User Assistance as a more apt spot for it.Message was edited by: Ex_Brit on 25/06/14 6:25:56 EDT PM