Windows® 7 Visual™ Quick Tips

3.14. Prevent Malicious Code from Running

You can prevent damage from some types of malicious programming by activating a feature that stops those programs from running code in protected portions of your computer's memory.

Windows 7 reserves some of your computer's memory as system memory, meant for use by Windows itself and by your programs. Windows reserves the rest of the memory for your open documents and other data. When programmers code software, they usually include fixed-size memory locations called buffers that hold data. Programs that require more data grab it from the hard drive and fill up the buffer.

Unfortunately, some poorly programmed software does not include a mechanism that watches for and prevents a buffer overrun — when ...