Around 2008 or so I seem to remember Kaspersky writing metadata to every file on the OS when scanning, requiring more frequent (and longer) drive defragging. No

Around 2008 or so I seem to remember Kaspersky writing metadata to every file on the OS when scanning, requiring more frequent (and longer) drive defragging. Nowadays I just use Defender on Windows 8, EMET and browser common sense. Occasionally firing up a sandbox for testing programs. Having NoScript enabled alone helps a great deal in preventing many exploits.