Since I installed McAfee on three of my systems they, at times, bog down to completely un-usable.
I've learned not to even attempt to use my PC for at least 10-20 minutes after it's powered on. McAfee simply bogs all three systems it's on to a dead-crawl. After the first update of the day, every day, I may be able to use my system.
If new software is installed, or use is attempted, again; forget about it. McAfee bogs down anything new to a crawl.
My systems vary from newer to older. McAfee doesn't care, it kills performance on all of them.
When running the system memory load is about 250MB! That's more than FOUR TIMES the system load of Outlook! It is easily the largest program running on my system. And it supposed to be a background application?!!
I've seen no other anti-virus that bogs my system down so completely, and certainly none of the free apps do the same. Releases of Symantec I've used are nearly undetectible in their overhead.
I can't imagine buying this software, and if it had cost money I certainly would be screaming for a refund!