Execution Protection by AMD, technology contained in AMD’s Athlon 64 chips, prevents a buffer overflow, a common method used to attack computers. A buffer overflow essentially overwhelms a computer’s defense systems and then inserts a malicious program in memory that the processor subsequently executes. The circuitry is already inside existing Athlon 64 chips, but it can’t be activated yet. That will occur when Microsoft releases Service Pack 2 for Windows XP early in the second quarter. Intel is putting a similar technology in Prescott, an enhanced version of the Pentium 4 expected next month.